Practice Test


1) Which of the following Mendel's law has not been proved to be true in all the cases?


2) The three important laws of heredity proposed by Mendel related to:


3) Which one of the following statement is true of Mendel's theory but not of Darwin's theory of natural selection?


4) Lethal genes are those which cause:


5) There is resemblance between parents and offspring but not the exact alikeness. This is because of:


6) When one gene pair hides the effect of other pair, this phenomenon is referred to as:


7) An exception to Mendel's law is:


8) Complementary genes show a ratio of:


9) If a dihybrid for character is crossed to a Homozygous recessive individual for the same character, the phenotypic ratio of the progeny would be:


10) Gene which have similar phenotypic effect when present separately but interact to produce a new phenotype when present together are known as:


11) In wheat, when a green plant was self-fertilized, the progeny has 20 green seedlings and 14 white seedlings. The above result indicated that the parents were:


12) If the genotype of an individual is AA Bb CC, it is a:


13) An individual heterozygous for two alleles (Aa Bb) produce two million spems; how many of the sperms will have both the recessive alleles:


14) If the frequency of a dominant phenotype in a stable population is 75%, the frequency of dominant allele in the population would be:


15) If two hybrids for the same quantitative character are crossed the phenotypic ratio of progeny would be:


16) From a single ear of corn, a farmer planted 200 kernels which produced 140 tall and 40 short plants. The genotypes of these offsprings are most likely:


17) An individual with genotype Aa Bb Cc will produce:


18) Mendel was successful in formulating the laws of inheritance whereas his predecessor were not because:


19) A test cross:


20) Mendel formulated the laws of heredity considering seven pairs of characters in the pea plant. If he had studied an eighth pair, the law which would have been altered as:


21) The segregation of paired hereditary factors that Mendel postulated occurs during:


22) The independent assortment of two pairs of genes located on non-homologous chromosomes, occur as a result of the random orientation of chromosome during:


23) Mendelian recombinations are due to:


24) Which one of the following character in man is controlled by a recessive gene?


25) The constriction on chromosomes where the spindle fibres attach during cell division are:


26) As a result of linkage and crossing over:


27) Gene P and Q are necessary for normal hearing. A deaf man marries a deaf woman and all their childern have normal hearing. The genotype of the parents are:


28) A plant with Aa Bb composition, on self-pollination results in which of the following genetic frequencies among the dominant phenotypes? AABB : AABb : AaBB : AaBb


29) "Like begets like" is an important and universal phenomenon of life, is due to:


30) "The father of genetic" G.J. Mendel is famous for propounding:


31) The frequency of mutant gene in a population is expected to increase if the gene is:


32) Genetic information is carried out by long chain of molecules made up of:


33) Mendel studied seven contrasting characters for his breeding experiments; which of the following character he did not study?


34) A normal plant suddenly started reproducing parthenogenetically, the number of chromosomes of the second generation compared to parent plant will be:


35) Why were pea plants more suitable than dogs for Mendel's experiments?


36) Suppose pea plant's tallness is dominant over dwarfness, to determine whether a tall pea plant is homozygous or heterozygous, it should be crossed with:


37) The term gene was given by:


38) The term back cross refers to:


39) A cross between unlike organisms is called as:


40) If Mendel has, by chance, chosen to study two traits determined by linked genes, he would have not been able to derive the:


41) In a monohybrid cross, 2 heterozygous individuals were crossed, phenotype ratio comes to be 2 : 1. It is due to:


42) Theory of inheritanace of acquired characters has not been approved by modern experimental biologist because:


43) Which one of the following is best illustrated by a cross of two bell-shaped Squash plants producing offsprings that are 25% round, 25% long and 50% bell shaped?


44) Monogenic traits give rise to:


45) Due to incomplete dominance, a cross between blue and white Andalusian Fowls results into:


46) A cross is made between the two organisms both of which have a genetic make up of Bb for a particular trait, and two offsprings are produced. The first offspring exhibit the dominant trait. What is the probability that the second offspring will exhibit the recessive trait?


47) Why did the test cross progeny of yellow vs. black mice gave 25% more offsprings that resulting from yellow vs. yellow mice:


48) The genes controlling seven traits in pea studied by Mendel were later found to be located on the following number of chromosomes:


49) Some people experience PTC paper on tongue as bitter, other as tasteless. This character is hereditary in nature. Suppose T stands for dominant gene and t stands for recessive gene. The genetic make up of a person who cannot taste is:


50) One of Mendel's pure strains of pea plants had green peas. How many different kinds of eggs could such a plant produce with regard to pea colour?


51) If the frequency of a recessive phenotype in stable population is 25% the frequency of the dominant allele in that population:


52) Coat colour in rabbit is an example of:


53) Height in man has been found to be influenced by interaction of:


54) Tallness (T) is dominant and dwarfness (t) is a recessive character. After crossing a number of Tt plants, a crop of 100 plants is obtained. Out of these 77 are tall and 23 are dwarf. What is the approximate number of hybrids?


55) In a gamete the gene of special fruit is represented by:


56) Which of the following forms represent a pair of contrasting character?


57) The alleles for coloured seed coat is dominant over that of white seed coat when flowers of a plant with white seed coat (ss) are pollinated with coloured seed coat (Ss), the colour of seed coat in developing seed would be:


58) When a female albino plant is crossed with normal green plant, all plants in the progeny are albino because:


59) Which one of the following is test cross?


60) Gene for red colour is completely dominant. A plant with genotype Rr is selfed, then the genotype of offspring would be:


61) An organism with two copies of the same allele is:


62) How many different kinds of gametes can an organism of genotype Xx, Yy, Zz produce?


63) A man receives his X chromosomes from:


64) In Mendel's dihybrid crosses, two pairs of factor (T/t) and (R/r) are located in:


65) When two genetic loci produce identical phenotypes in cis as well as trans position, they are considered to be:


66) The phenomenon in which an allele of one gene suppresses the activity of an allele of another gene is known as:


67) Gamete contains which of the following:


68) Human skin colour and blood groups are controlled by:


69) Sickle cell anaemia is an example of:


70) Which condition of zygote is lethal:


71) The frequency distribution curve of skin colour in man is:


72) Blood group 'O' has:


73) According to Mendel there are:


74) Botanical name of Snapdragon is:


75) A blood group is due to:


76) Assume cross between red and white flowered plants which produce pink:


77) Allele is called:


78) Autosomes are:


79) Back cross is:


80) A heterzygous individual carrying a recessive sex-linked gene is called:


81) Pioneer of modern genetics is:


82) Mendel selected pea plant for his experiments because it has:


83) Process of transmission of characters from one generation to another is called:


84) Genetics deals with:


85) Dihybrid plant is:


86) When one member of a pair of allelic genes expressed itself as a whole, it is a case of:


87) The first generation of a given cross is known as:


88) Gamete is:


89) Genotype of individual is:


90) Fraternal twins are produced when:


91) "Theory of pangenesis" to explain mechanism of heredity was given by:


92) The I.Q. of a genius ranges from:


93) The genetic ratio is termed as:


94) I.Q. is the ratio of mental age to:


95) Sex of unborn mammal can be predicated by:


96) Criminal syndrome:


97) Galton is associated with:


98) The term gene refers to:


99) Who connected cytology with genetics:


100) The sum total of genes in a population is known as:


101) Which is wholly genetic trait?


102) A couple with blood types A and B may have childern with which of the blood types:


103) By his ancestral profession Mendel was a:


104) Word heredity is derived from the Latin word 'Hereditas' which means:


105) Preformation theory of heredity was given by:


106) Who proposed the theory of Epigenesis?


107) The scientist who propounded the theory of pangenesis/gemmules was:


108) Who observed that offspring of hybrids resemble their grandparents more than their parents?


109) One of them believed in the tendency of characters to lose strength or gain strength:


110) Mendel's work was republished in Flora in the year:


111) The scientist who worked on Garden Pea before Mendel was:


112) A pair of contrasting characters is called:


113) Which organisms are used for experimental genetics?


114) One of the following ratios represents a test cross:


115) If a plant is heterozygous and is designated Bb. The probability of b gamete fertilizing either B of b is:


116) When two individuals are similar in external appearance but different in their genetic make up, they are called as:


117) Mendel succeeded in enumerating the laws of genetic inheritance whereas investigatiors before him failed, because:


118) Two bean seeds collected from a pod were sown in a pot and kept in a favourable condition. After some time it was observed that one plant has grown ten times the growth of another. This difference may be due to the difference in their:


119) Who proposed the hypothesis that every organ of an animal body emits some sort of vapours which unite to form a new individual?


120) In a dihybrid cross between two varities of sweet pea, (BBLL) and (bbll) and hybrid test crossed Bateson and Punnet found phenotype ratio of 7 : 1 : 1 : 7. This ratio throws a light on the occurrence of:


121) If two dihybrids for the same quantitative traits crossed, the phenotypic ratio of the progeny would be:


122) In Himalayan Rabbit the pigmentation of extremities can disappear when?


123) Individual with Aa or AA may not express dominant phenotypes due to:


124) Sex linked traits can be found out through:


125) In a 9 : 3 : 3 : 1 dihybrid phenotypic ratio, the number of hybrid dominant as both ratios:


126) In Primrose despite the presence of dominant allele of red flower colour, the flower appear white when:


127) How can you determine whether the phenotype of an individual is pure homozygous or 'impure' heterozygous?


128) In Lathyrus the purple colour of flower is controlled by two dominant non-allelic genes-C and P which are not able to express themselves alone. It is an example of:


129) Factor hypothesis is another name for:


130) Ratio 9 : 7 is obtained for a dihybrid cross involving:


131) Gametes of Aa Bb individual can be:


132) A tobacco plant which is heterozygous for albinism (a recessive trait) is self-pollinated. If 1200 seeds are subsequently germinated, how many of the seedlings would have parental genotype?


133) In humans blue eye colour (bb) is recessive to brown-eye colour (BB). A brown-eyed man has a blue-eyed mother. What could be the possible genotypes of his father?


134) The chequer-board method to work out the Mendelian crosses was introduced by:


135) Mating between black rats of identical genotype produced offspring-14 creamy, 47 black and 19 albino. What epistatic ratio is expected and what type of epistasis is operative?


136) Selection will not eliminate a lethal recessive gene from a large population because:


137) Human skin colour is determined by quantitative genes. The theory was put forward by:


138) Polygenic inheritance was first studied by:


139) Pseudoalleles are:


140) The offspring of two creeper chicken are:


141) Which one is a hereditary disease?


142) A modified dihybrid Mendelian ratio of 9 : 3 : 4 shows:


143) Sex is a trait which:


144) RR (red) Antirrhinum is crossed with white (WW). Offspring RW are pink. This is an example of:


145) Which genotype characterises an organism that is heterozygous for two genes?


146) With respect to the ABO group there are found major blood types because this blood group is determined by:


147) Mr. Kapoor is heterozygous for one autosomal gene pair Bb and he carries a recessive X-linked gene d. What will be the proportion of his sperms bd?


148) Isoalleles are:


149) In homozygous state, sickle cell disorder shows:


150) Some well-planned experiments on heredity were performed much before Mendel by:


151) Cuneot crossed two yellow coloured mice which never bred true and received a ratio of 2 : 1 (yellow, brown). It is due to:


152) Which of the following scientists is not associated with rediscovery of Mendelism?


153) A golden flower female plant was crossed with a white flowered male plant. The progeny was golden. In a reciprocal cross the progeny was white flowered. Which of the following alternatives correctly explain it?


154) Who among the followings demonstrated and got first experimental proof of polygenic inheritance?


155) If a dihybrid for quantitaitve character is crossed to a dominant homozygous for the same character, the pehnotypic ratio of the progeny would be:


156) He pointed out that childern may resemble their grandparents rather than their parents. Who?


157) Genotype-phenotype concept was formulated by:


158) Recessive characters are expressed:


159) Which of the following shows codominance?


160) In summer squash, a cross between two pure spherical, fruit types may yield a progeny having disc-shaped fruits due to:


161) Which of the following is true for reverse genetics?


162) Haploids are able to express both recessive and dominant alleles/mutations because there are:


163) A single recessive trait which can express its effect should occur on:


164) A dark stained body near nuclear envelope from a buccal cavity all indicates:


165) RrYy yield gamete types:


166) When one pair of genes can completely mask the expression of another pair of genes, the effect is referred to as:


167) Normal hearing and speech in man is due to:


168) If a negro marries a white skin female, the mulattoes are born. If such mulattoes intermarry, progeny will show a gradual gradation of skin colour in ratio of:


169) Wheat kernel colour and skin colour inheritance in man are examples of:


170) Appearance of walnut comb in poultry in a cross between pure Pea-comb and Rose-comb animals is due to:


171) When reproduction takes place by the fusion of gametes of different parents the resulting offspring would be:


172) How could Mendel demonstrate that hybrids have equal contribution from both the parents?


173) In Rice, green colour of leaf can develop either in the presence of recessive allele p or another gene I. The latter gene is:


174) Epistasis was first studied by:


175) Validity of Mendel's laws is only when:


176) If a character is always transmitted directly from father to all his sons and from them to all their sons, then which chromosome carry gene for this character:


177) The genetic basis of haemophilia, so common within European royal families was revealed by studies of:


178) The lack of pigmentation is called albinism. It is due to a recessive allele 'a'. Two normal parents have albino child. What will be the probability of the next child to be albino?


179) Some genes (alleles) despite being detrimental to the organism, propagate themseleves e.g. , sex ratio (SR) in Drosophila or MD (male drive) in mosquito, SK (spore killer) in Neurospora. These genes are called:


180) Different mutations referrable to the same locus of a chromosome give rise to:


181) In summer squash, the fruit colour can be white, yellow and green. The appearance of white colour is due to a dominant gene W. The latter is:


182) Onion bulb shows white colouration instead of red-yellow pigmentation when allele of another gene is present. It is an example of:


183) Degree or extent to which a given genotype is expressed phenotypically in a particular individual, is called:


184) Reproductive blood theory of heredity was proposed by:


185) Agouti, Chinchilla, Himalayan and albino coat colour in rabbits are controlled by:


186) When two alleles are brought together in a hybrid, one of them expresses itself completely at the expense of the second it is due to Mendel's:


187) If two opposite alleles (e.g., red and white) comes closer together, one of the two (red) finds morphological expression, masking other in the body of the organism, this fact is described as:


188) The term genotype was given by:


189) Lethal genes are defined as:


190) Segregation of genes takes place during:


191) Acetabularia has been used as an experiment material to prove that:


192) Which law would have been violated if Mendel had chosen eighth character in garden pea?


193) Complementary genes were discovered by:


194) A cross between two white flowered varities of sweet pea yields purple flowered plants due to:


195) Usually the recessive character is expressed only when present in a double recessive condition. However, single recessive gene can express itself in human beings when the gene is present on:


196) In an experiment on pea plants round yellow seeds were crossed with plants producing wrinkled green seeds. What will be the phenotypic ratio of the progeny?


197) O-group mother with O-group child sue AB group man for fathership of child. What is true?


198) An offspring of two homozygous parents differing from one another by alleles at one gene locus is known as:


199) Plants can be made disease resistant by:


200) If an allele is dominant, indicate the genotype in which the dominance becomes expressed?


201) Polymorphism is mainly due to:


202) Continuous genetic variations are produced by:


203) The alleles that produce independent effects in heterozygous condition are called:


204) Correct statement about failure of hybrid formation is:


205) Which of the following causes haemolysis in new born?


206) Sickle cell anaemia is caused due to:


207) If Mendel has studied the 7 traits using a plant with 12 chromosomes instead of 14, in what way would his interpretation have been different?


208) How many different types of genetically different gametes will be produced by a heterozygous plant having the genotype: AA Bb Cc?


209) Human skin colour is controlled by several gene pairs. Let us assume here that there are just three gene pairs on different chromosomes and that for each pair there are two alleles - an incompletely dominant one that codes for melanin deposition and an incompletely recessive one that codes for no melanin deposition. If a very dark skinned peron marries a very light skinned woman, what will be the chance that their offspring will have very dark skin?


210) Two pea plants were subjected cross pollination. Of the 183 plants produced in next generation, 94 plants were found to be tall and 89 plants were found to be dwarf. The genotypes of the two parental plants are likely to be:


211) Mendel studied inheritance for seven pairs of characters in pea for a study of independent assortment, seven characters can be arranged in 21 possible pairs. If you are told that in one of these 21 pairs, independent assortment was not observed in repeated later studies, what would be your reaction?


212) Gametes are never hybrid? It is a statement of law of:


213) Which is correct about traits chosen by Mendel?


214) In a certain plant, red fruit ( R ) is dominant over yellow fruit ( r ) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype is crossed with a plant rrtt genotype, what will be the percentage of tall plants with red fruits in the progeny?


215) Mendel obtained wrinkled seeds in pea due to deposition of sugars instead of starch. It was due to which enzyme?


216) Ratio of complementary genes is:


217) When dominant and recessive allele express itself together, it is called:


218) What is correct for Blood group 'O'?


219) Sickle cell anaemia induce to:


220) Independent assortment of genes does not take place when:


221) Two non-allelic genes produce the new phenotype when present together but fail to do so independently, then it is called:


222) Two individuals with similar external appearance but different genetic make up have the similar:


223) Two crosses between the same pair of genotype or phenotype in which the sources of the gametes are reversed in one cross, is known as:


224) The gene controlling the seven pea characters studied by Mendel are now known to be located on how many different chromosomes?


225) Which one of the following traits of garden pea studied by Mendel was a recessive feature?


226) When a cluster of genes show linkage behaviour they:


227) Alleles represent:


228) If a cross between two plants give 50% tall and 50% dwarf progeny, then the parents genotype are:


229) A person with blood group A has:


230) Self-fertilising trihybrid plants form:


231) When a tall and red flowered individual is crossed with a dwarf and white flowered individual, phenotype of the progeny will be:


232) Genetic counsellors can identify heterozygous individuals by:


233) If a homozygous red flowered plant is crossed with a homozygous white flowered plant, the offsprings would be:


234) Which of the following term represents a pair of contrasting character?


235) Following are the statements, which are either true or false. Examine them and find out the incorrect answer. Mendel has selected Pisum sativum (garden pea) as his experimental tool because:


236) The genetic ratio of 9 : 3 : 3 : 1 is due to:


237) When cross is made between two species of the same genus, then the cross is known as:


238) Epistasis is the:


239) When one gene hides the effects of another gene, the interaction factor is known as:


240) A genetically dwarf plant made tall by use of Gibberellin was crossed with a plant purely tall. Then the progenies would be:


241) Which of the following is considered as a recessive character of Mendel?


242) Which of the following characters chosen by Mendel are recessive?


243) Which is functional unit of inheritance?


244) Heterosis requires:


245) The phenotype ratio obtained in quantitative inheritance of a dihybrid cross is:


246) Mating between two individuals differing in genotype to produce genetic variation is called:


247) Primary source of allelic variation is:


248) In order to find out the different types of gametes proudced by a pea plant having the genotype AaBb, it should be crossed to a plant with the genotype:


249) At a particular locus frequency of 'A' allele is 0.6 and that of 'A' allele is 0.6 and that of 'a' is 0.4. What would be the frequency of heterozygotes in a random mating population at equilibrium?


250) Test cross involves:


251) How many different kinds of gametes will be produced by a plant having the genotype AABbCC?


252) In maize, hybrid vigour is exploited by:


253) Which one of the following is an example of polygenic inheritance?


254) A common test to find the genotype of a hybrid is by:


255) Inheritance of skin colour in humans is an example of:


256) A human male produces sperms with the genotypes AB, Ab, aB, and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?


257) Indicate, the inheritance of which of the following is controlled by multiple alleles:


258) Which of the following is related to heamophilia?


259) In a green pod of pea the seed-coat colour changed from grey to white. This is an example of:


260) The ratio of recessive epistasis:


261) Epistasis was discovered by:


262) A black dog heterozygous for coat colour is crossed with white bitch recessive homozygous. Progeny will show black to white offsprings in the ratio of:


263) When an individual possesses both alleles of its phenotypically dissimilar parent, it is called:


264) In a pig dominant allele B produces black colour and its recessive allele b produces white. What would be the probable genotype of the offspring when a cross is made between individuals heterozygous for colour?


265) A dominant lethal gene is that which:


266) If the cell of an organism heterozygous for two pairs of genes represented by Aa, Bb undergoes meiosis, then the possible genotypic combination of gametes will be:


267) In order to determine whether variations of a character in a population were genetically controlled, the most appropriate producers will be to:


268) In cucurbita, W is epistatic over Y and y gene normally responsible for yellow and green coloured fruits. It produces white flowers. What is ratio of fruits in progeny of a cross WwYy + wwYy


269) Hemolytic jaundice is caused due to a dominant gene but only 10 percent of the people actually develop the disease. A heterozygous man marries a homozygous normal woman. What proportion of the childern would be expected to develop the hemolytic disease?


270) Two tall pea plants were crossed. If is produces 9 tall and 3 dwarf plants, what would then be the genotype of tall plants?


271) Polymorphic variations are due to:


272) In human an example of sex-linked trait is:


273) Wife is PTC non-taster and husband is PTC taster. Their son is taster but daughters are non-tasters. This is not a sex linked trait. Which pedigree is correct?


274) A tall red flowered pea plant after crossing with a dwarf white-flowered plant yields only tall red-flowered plants. A test cross shall give a ratio of


275) Mendel did not propose the theory of -


276) Pleiotropic gene has -


277) An organism with two identical alleles is said to be -


278) Who is considered as father of genetics ?


279) A cross between hybrid and recessive parent is


280) Inheritance of skin colour in human beings is an example of -


281) Which of the following proved an exception to Mendel's principles ?


282) When a gene pair hides the effect of another, the phenomenon is called -


283) An allele is dominant, if it is expressed in -


284) The ratio 9 : 7 is produced due to -


285) How many contrasting characters were selected by Mendel ?


286) Mendel's monohybid ratio is -


287) The different forms of a gene are called -


288) Mendel's dihybrid ratio is


289) Two dominant independently assorting genes react with each other. They are


290) A child with mother of A group and father of AB group, will not have the following blood group -


291) A cross between parents with AaBB and aaBB genotype will form -


292) How many types of gametes will be produced by individuals of AABbcc genotype ?


293) Crossing over in diploid organisms is responsible for


294) ABO blood groups is determined by


295) A test cross enables one to


296) In keeping with the law of independent assortment what is actually assorted ?


297) In Mendel's experiments the alleles were


298) In the AB blood group the two genes are


299) In sweet pea, the epistatic interaction between the genes for purple and white colour produced the two colours in the ratio -


300) Human skin colour is controlled by


301) Polygenes are


302) Multiple alleles control the character of


303) How many types of gametes will be produced by individuals having genotype AaBbCc ?


304) Gene located on the same locus but having different expressions are


305) Which one of the following is a sex-linked disease?


306) Linkage was discovered by


307) The substance, which causes a definite change in genes is called


308) A family of five daughters only is expecting sixth issue. The chance of its being son is


309) Haemophilia is more common in males because it is a -


310) Chiasma represents the site of


311) A single recessive trait which can express its effect should occur on


312) A woman with one gene for haemophilia and a gene for colour blindness on one of X chromosomes marries a normal man. How will the progeny be ?


313) Substitution of a purine nucleotide by pyrimidine nucleotide is called


314) Mutations used in agriculture are commonly -


315) Harmful mutations does not get eliminated from gene pool because


316) In a dihybrid cross between two heterozygotes AaBb X AaBb, if we get 3 : 1 ratio among the offsprings, the reason for this may be


317) Trisomy has a chromosome complement of -


318) Triticale has been produced by intergeneric hybridization between


319) Which one of the following would represent allotetraploid ?


320) The meaning of syndrome is related to


321) The Klinefelter's syndrome has chromosomal constituent -


322) What will be the number of linkage groups in a cell having 2n = 20 ?


323) In which stage crossing over takes place ?


324) Which of the following truly represents a heterozygous organism ?


325) Which one of the following is sex-linked disease ?


326) The exposure of X-rays enhance the frequency of


327) Which one of the following is the genotypic ratio in monohybrid cross ?


328) The combined form of coupling and repulsion is -


329) How many pairs of autosomes are found in human ?


330) Which of the following statements is true about Mendel ?


331) Imagine that in a maize plant, the factors for controlling seed coat and seed shape are present on the same chromosome very close together. Performing dihybrid experiments with these characters, Mendel would not have been able to arrive at the idea of-


332) If Mendel had studied the 7 traits using a plant with 12 chromosomes instead of 14, in what way his interpretation would have been different ?


333) In maize plants, two alleles of the gene for seed colour exist. Purple (P) is dominant to yellow (p). A backcross (testross) was carried out to determine the genotype of a certain purple plant. Which of the following is correct ?


334) In mice, Y is the dominant allele for yellow fur and y is the recessive allele for grey fur. Since Y is lethal when homozygous, the result of cross Yy x Yy will be


335) In mice, black coat colour (allele B) is dominant to brown coat colour (allele b). The offspring of a cross between a black mouse (BB) and a brown mouse were allowed to interbreed. What percentage of the progeny would have black coats ?


336) In fruit flies, long wing is dominant to vestigial wing. When heterozygous long-winged flies were crossed with vestigial winged flies, 192 offspring were produced. Of these 101 had long wings and 91 had vestigial wings. If an exact Mendelian ratio had been obtained, then the number of each phenotype would have been


337) In a certain plant, yellow fruit colour (Y) is dominant to green (y) and round shape ( R ) is dominant to oval ( r). The two genes involved are located on different chromosomes.
Which of the above will result when plant YyRr is self-pollinated ?


338) In a certain plant, yellow fruit colour (Y) is dominant to green (y) and round shape ( R) is dominant to oval ( r). The two genes involved are located on different chromosomes.
Which of the above will result when plant YyRr is backcrossed (testcrossed) with the double recessive parent ?


339) In a certain species of sweet pea plant, flowers are either purple or white. Colour is determined by two unlinked genes. The alleles of the first gene are X and x; those of the second gene are Y and y.
In order to bear purple flowers, a plant must possess at least one X and one Y allele. Those genotypes which fail to do so, result in the formation of white flowers.
If two purple-flowered plants of genotype XxYy are crossed then the expected phenotypic ratio of offspring would be


340) In snapdragon plants, broad leaf is completely dominant to narrow leaf whereas red flower colour is incompletely dominant to ivory. (The genes for leaf width and flower colour are not linked).
If a plant which is heterozygous for both genes is crossed with a true-breeding broad-leaved red-flowered plant, then the expected proportion of broad-leaved plants with pink flowers amongst the offspring would be


341) In humans, the gene for red blood corpuscle shape (alleles elliptical E and normal e) is linked to the gene for Rhesus blood (alleles Rhesus positive R and Rhesus negative r).
A person with alleles E and R on one chromosome and e and r on its homologous partner will definitely produce gametes with the genotypes


342) In humans, the gene for red blood corpuscle shape (alleles elliptical E and normal e) is linked to the gene for Rhesus blood (alleles Rhesus positive R and Rhesus negative r).
If crossing over occurs between these two genes, then the two additional types of gametes that could result are


343) Linkage is


344) X and Y chromosomes are


345) Observe the sex determination in the following.
(I) Human males = XY
(II) Female hen = ZW
(III) Male Drosophlla = XY
(IV) Male grasshopper = XO
(V) Male birds = ZZ
Male heterogamety = A
Female heterogamety = B
Male homogamety = C
Which of the following combination is correct -


346) Idenify the steps in cross in pea.
A. Removal of anthers, B. Transfer ofPollen,
C. Raising the next generation


347) Wife is PTC nontaster and husband is PTC taster. Their son is taster but daughters are nontasters. This is not a sex linked trait. Which pedigree is correct ?


348) Which of the following male animals is NOT heterogametic ?


349) A sex-linked allele NEVER passes from a


350) The question refers to eye colour in fruit fly. In this sex-linked trait, the allele for red eye is dominant to that for white eye.
If a red-eyed male is crossed with a white-eyed female, their offsprings will occur in the ratio


351) This question refers to eye colour in the fruit fly. In this sex-linked trait, the allele for red eye is dominant to that for white eye.
If a heterozygous red-eyed female is crossed with a white-eyed male, what percentage of the female offsprings will be white-eyed ?


352) Haemophilia is a condition in which blood fails to clot or clots only very slowly. Studies of this human sex-linked trait show that


353) Which of the following offspring could be produced by a normal homozygous female and a haemophiliac male ?


354) A human female will definitely be a colour blind if


355) A mutation is a


356) Which of the following statements is NOT correct ?


357) A comparison of the karyotypes of a normal human male and a male sufferer of Down's syndrome shows the latter to possess


358) Klinefelter's syndrome results from the fusion of


359) A species of plant is known to have a diploid chromosome number of 14 in each of its cells. Which of the following would be the number of chromosomes found in each cell of one of its polyploid relatives ?


360) Polyploid wheat does NOT normally show an increase in


361) Linkage was discovered by -


362) Bateson used the terms coupling and repulsion for linkage and crossing over. Name the correct parental or coupling type along with its cross over or repulsion :


363) Which of the following is suitable for experiments on linkage ?


364) Linkage reduces the frequency of -


365) Two linked genes a and b show 20% recombination. The individuals of a hybrid cross between ++/++ x ab/ab shall show gametes :


366) A and B genes are linked. What shall be genotype of progeny in a cross between AB/ab and ab/ab?


367) Two genes situated very close on the chromosome show -


368) Given are the statements regarding linkages of genes :
(I) The strength of the linkage is determined by the distance between the 2 genes in question.
(II) The strength of the linkage is directly proportional to the distance between the two genes.
(III) The two genes re said to be linked when they fail to show independent assortment.
Out of these statements :


369) Which of the following statements about mutations is false ?


370) Two organisms that are true-breeding for a certain genetic characteristic are mated and their offsprings analyzed. Which of the following statements about this situation is true ?


371) A pea plant that is heterozygous for the flower gene makes gametes. What is the probability that one of its gametes contains the recessive white allele for flower colour ?


372) Consider a gene that has two alleles and shows complete dominance. When two heterozygotes for this gene breed, they have a 25 percent chance of producing a homozygous recessive offsprings. The next time they breed, what are the chances that they will once again have a homozygous recessive progeny ?


373) In a particular plant, two genes control leaf shape and colour. Round leaves ( R ) are dominant to jagged leaves ( r ). Yellow fruits (Y) are dominant to white fruits (y). A true-breeding round-leaved, yellow-fruited plant is mated with a jagged-leaved, white fruited plant. What are the genotypes of the plants involved in this cross ?


374) The phenomenon is which the genes have two or more alleles that are common in the population is known as


375) If an inheritable mutation is observed in a population at high frequency, it is referred as


376) Go through the statements.
(I) The graphical representation to calculate the probability of all possible genotypes of offsprings in a genetic cross was developed by Gregor Mendel.
(II) Failure of segregation of chromatids during cell division results in aneuploidy.
(III) Additional copy of 'X' chromosome in males results in Klinefelter's syndrome.
(IV) Closely located genes in a chromosome always assort independently resulting in recombinants.
(V) According to Mendel, recessive character never blend in heterozygous condition.
(VI) Failure of cytokinesis after DNA replication results in polyploidy.
(VII) A person affected with phenylketonuria, lacks an enzyme that converts the amino acid phhenylalanine into tyrosine.
How many wrong statements are given in above statements.


377) Which of the following is not a dominant trait ?
(A) Colour blindness, (B) Rh factor, ( C ) Albinism, (D) Haemophilia


378) Mendel proposed -
(A) dominance, (B) segregation, ( C) incomplete dominance, (D) independent assortment


379) Which contributed to the success of Mendel ?
(A) Selection of pea plant, (B) His knowledge of biology, ( C) Consideration of one character at one time, (D) He had knowledge of linkage


380) What is not true of law of independent assortment ?
(A) Applicable to all the dominant alleles
(B) Applicable to all genes on the same chromosome
( C) Not applicable to genes present on the same chromosome
(D) Applicable to all recessive alleles


381) Alleles represent
(A) different forms of a gene
(B) same loci on homologous chromosomes
( C) two or more forms
(D) none of these


382) Genes for colour blindness in humans are carried by
(A) abnormal sex, (B) father, ( C) mother, (D) none of the above


383) Which of the following is a mutagen ?
(A) lonizing radiations, (B) Gamma rays,
(C) UV rays,
(D) Nitrous acid


384) Chromosomal aberration occurs due to
(A) deletion,
(B) duplication,
(C) inversion,
(D) translocation


385) Which is genetically-transmitted diseases ?
(A) Colour blindness, (B) Haemophilia,
(C) Musculardystrophy,
(D) None of these


386) Which is the example of chromosomal disorder ?
(A) Turner's syndrome, (B) Down's syndrome, (C) Klinefelter's syndrome,
(D) None of the above


387) (A) sutton united the knowledge of chromosomal segregation with Mendelian principles and called it the chromosomal theory of inheritance.
(B) Genes are the units of inheritance
( C) There are 6 different alleles which determine ABO blood types.
(D) The phenotypic ratio of Mendelian monohybrid cross is 3 :1.


388) Drosophila melanogaster (fruit fly) is a suitable for genetical studies because
(A) It can be grown on simple synthetic medium in the laboratory
(B) Lifecycle is short (about 2 weeks)
( C) A single mating produces large number of progenies.
(D) Visible sexual dimorphisms and many types of genetical variations can be easily observed.


389) (A) genetic maps are extensively used as starting point in the sequencing of whole genome as was done in case of the Human genome sequencing project.
(B) UV-rays can cause mutation in organisms
( C) Deletion and insertions of base pairs of DNA cause frame-shift mutations.
(D) Mendelian disorders may be dominant or recessive.


390) Which one / ones is /are correct about the person suffering from klinefelter's syndrome ?
(A) It is a case of trisomy.
(B) The suffer has 47 chromosomes.
( C) He / She is fertile
(D) Tall stature with brest development.


391) (A) Mytonic dystrophy is an autosomal dominant trait.
(B) Sickle cell anemia is an autosomal recessive trait.
( C) Cystic fibrosis is a Mendlian disorder.
(D) Failure of segregation of chromatids during cell division cycle results in the gain or loss of a chromosome(s) called aneuploidy.


392) 1 : 1 : 1 : 1 ratio of progenies can be obtained if the plants for crossing are :
(A) TTRR X ttRR
(B) TtRr X ttrr
(C ) TtRR X ttrr
(D) Ttrr X ttRr


393) Which one / ones is/ are correct about the gametes produced by TtRr ? It is not the case of linkage
(A) 4 types of gametes will be formed
(B) The percentage of each gamete is 25
(C ) Each gamete is diploid
(D) Out of 4 gametes 2 gametes have all dominant genes


394) If a man of blood group A marries a woman of blood group B, their children can be of the blood group


395) (A) Linkage prevents segregation of genes present on the same chromosomes
(B) XY sex chromosomes were discovered by Nettie Stevens
( C ) Complete linkage has been reported in male Drosophila
(D) Term linkage was given by Correns


396) Crossing over involves


397) If Tt Pea plant mates with Tt Pea plant what will be characteristic / character of offsprings ?
(A) 75% plants tall
(B) 25% plants dwarf
( C) 50% plants are homozygous
(D) 50% plants are heterozygous


398) In case of Mirabilis Tt Rr (pink) plant is self crossed, what will be the characteristic / characteristics of the result ?
(A) 75% plants are tall
(B) 25% plants will have Red flower
( C) 25% plants will have white flower
(D) 50% plants will have pink flower


399) In 1900 Mendelism was rediscovered by
(A) Morgan
(B) de Vries
( C) Correns
(D) Tschemak


400) Patterns of sex linked inheritance conform to
(A) Mendel's concept of dominance & recessive
(B) Mendel's law of segregation
( C) Mendel's law of parental equivalence
(D) None


401) The recombination frequency
(A) between two genes cannot exceed 50%
(B) is directly proportional to the distance between linked genes
(C ) helps to determine the relative order of genes and distances between them on a chromosome
(D) is equal to map unit


402) In a family pedigree :
(A) Circles represent males
(B) Squares represent females
(C ) A solid / blackened symbol represents the individual with a recessive trait always
(D) Mating is shown by a horizontal line connecting a male and a female symbol


403) Polyploidy
(A) is the occurrence of more than 2 sets of chromosomes or genome
(B) is resulted due to non-formation od spindle fibres
(c ) is resulted due to failure of cytokinesis
(D) is more common in plants


404) Test cross in Drosophila that is cross between Red eyed hybrid female and white eyed male showed
(A) red eyed female = 25%
(B) White eyed female = 25%
(C ) Red eyed male = 25%
(D) White eyed male = 25%


405) Mendel's laws were able to predict accurately the pattern of inheritance for situations in which


406) Which of the following statements summarizes an observation Gregor Mendel made in refutation of the blending theory of inheritance ?


407) Which of the following statements is a basic summary of Mendel's laws ?


408) Which of the following expresses Mendel's law of equal segregation ?


409) Which of the following statements is true ?


410) Which of the following pair of words can be used correctly to describe alleles ?


411) If T = tall and t = short, the genotype of an animal with the 'short' phenotype must be


412) If a person has one copy of each of two different alleles for a given gene, the person is __ for the trait.


413) Which of the following symbols correctly represents a person who has a homozygous genotype ?


414) Which of the following symbols represents a potential genotype of a standard (nongamete) body cell ?


415) Which of the following symbols represents a recessive allele ?


416) Which of the following statements is generally true ?


417) Which of the following symbols represents the parental generation of a cross ?


418) A punnett square is used to


419) If the P allele is incompletely dominant over the p allele, what percentage of the resulting offspring will have the dominant phenotype when Pp and Pp individuals mate ?


420) If the D allele is completely dominant over the d allele, what percentage of the offspring will have the dominant phenotype when Dd and Dd individuals mate ?


421) Your mother decides she would like some of the pink flowered roses. Which cross would give you the most pink flowered plants?


422) A plant with the genotype ss mates with itself and produces all ss offspring. The parental plant is


423) Most human genetic characters are


424) The best way to get accurate results from a probability exercise is to


425) Which of the following statements is true?


426) A population has a 1 : 1 ratio of alleles for a given gene (the dominant and recessive alleles are present in equal numbers). Are more individuals affected if the alleles is lethal when present in the dominant condition or in the recessive condition ?


427) Is it possible for two organisms with the same genotype to have different phenotypes in same environment ?


428) What is the meaning of 'dominant' and 'recessive' relative to alleles for a given gene ?


429) Mutation may be harmful, beneficial or have little impact. WHich of the following choices states one reason that a mutation might have little impact ?


430) The leaf colour of a certain plant is controlled by one gene. For that gene, the allele G = orange and g = green. You have a plant with orange leaves, but do not know whether that plant's genotype is GG or Gg. if you cross your unknown plant with one of the plants whose genotype is listed below, you will be able to determine your unknown's genotype ? With which plant should you cross it ?


431) Which of the following choices represents the genotype of an individual organism ?


432) Which of the following represents the gametes that can be formed by an individual with the genetic makeup: FfGgHH


433) Cystic fibrosis is caused by a recessive gene. If C = normal and c = cystic fibrosis, how can a child with cystic fibrosis have two parents that do not have cystic fibrosis ?


434) The chance of a parent passing on a given gene to a child __ each time he or she has another child.


435) Which of the following statements is not true ?


436) __ represent(s) an example of how applied genetics is becoming an increasingly important area of biology.


437) Mendel's primary contribution to our understanding of genetic inheritance was


438) In Mendel's model of particulate inheritance, what he called 'particles' we now refer to as


439) Being able to use a Punnett square to track the pattern of inheritance in a two-characteristic cross (e.g., pea seed colour and seed shape) demonstrates Mendel's idea of


440) A chestnut-colored horse is mated with a cremello-colored horse. Over a 10 year period, all of their offsprings are palominos. This pattern of inheritance is best explained by


441) The above figure shows


442) The pie chart shows the results of a survey of the incidence of blood group A, B, AB & O amongst people in India.
Which of the conclusions can be deduced from the diagram ?


443) Mutation can be induced with


444) Which one of the following conditions correctly describes the manner of determining the sex in the given example ?


445) A person with unknown blood group under ABO system, has suffered much blood loss in an accident and needs immediate blood transfusion. His one friend who has a valid certificate of his own blood type offers for blood donation without delay. What would have been the type of blood group of the donor friend ?


446) To study the natural phenomenon of inheritance, Mendel selected the pea plants. Which of the following properties were suitable for his studies ?
(I) Plants were easily grown in garden soil with a considerably shorter generation time.
(II) Plants would easily self pollinate or cross pollinate in nature.
(III) Many parts of the plant such as pod, seed, flower and cotyledons showed distinct phenotypes.
(IV) Pea plants do not require the true-breeding lines for hybridization experiments.


447) In sickle cell anemia, substitution occurs in between


448) If Mendel has studies10 traits using a plantwith 14 chromosomes, he would have


449) Study the two cases carefully.
The correct interpretation of the 2 cases is


450) Person I (P-I) --- Shows tall stature with feminised character (Gynacomastia)
Person II (P-II) --- Shows short stature, Sterility underdeveloped feminine characters, webbed neck
Person III (P-III) --- Shows short staturd, small head, furrowed tounge, creased broad palm, retarded physical psychomotor and mental development.
Identify the syndromes:


451) (I) Enborn error of metabolism
(II) Homozygous recessive autosomal alleles chromosome12 cause absence of specific enzyme
(III) A specific amino acid does not change into tyrosine
(IV) Accumulation of phenylpyruvic acid and other derivatives leading to mental retardation.
The above facts refer to


452) Incomplete dominance occurs when


453) Find out the wrong option :


454) What fraction of offsprings of the cross AaBbDdEEFf X AaBBDdEeFf are homozygous for all the genes, assuming that they are on different chromosomes?


455) Choose the correct incorrect option :


456) Which of the following options is wrong ?


457) Select the odd one out w.r.t. chromosomal theory of inheritance.


458) Morgan and drosophila as experimental materialbecause


459) Find the one one out w.r.t. complete linkage


460) Find the correct statement w.r.t chromosomal mapping


461) Select the incorrect statement w.r.t pedigree analysis


462) Starch grain size in garden pea, flower colour in 4'O clock plant and heterozygous individual for sickle cell aneamia are the examples of


463) Morgan carried out several dihybrid crosses in fruit fly and found that


464) Mr Siddharth is suffering from hypertrichosis and phenylketonuria. His father is heterozygous for phenylketonuria. The probability of Siddharth's sperm having one recessive autosomal allele and holandric gene is


465) Consider the following statements (A-D) each with one or two blanks.
(A) __(I)__ are commonly observed in cancer cells.
(B) During __(II)__ purine is replaced by another purine.
(C) Failure of __(III)__ after telophase stage of cell division results in an increased in whole set of chromosome in an organism and this phenomenon is known as __(IV)__.
(D) In Down's syndrome, the affected individual is short statured wiith __(V)__ round head and partially open mouth.
Which one of the following options gives the correctly fill sum of the respective blank numbers from (I) to (V) in the statements ?


466) If the frequency of an autosomal dominant allele is 0.6. Calculate the frequency of recessive phenotype in a population of 10000.


467) Test cross in plants or in Drosophila involves crossing


468) Mendel studied which type of inheritance


469) In which of the following combinations conclusion of independent assortment does not apply


470) Mendelian genetics applies on


471) A test cross is carried out to


472) The idea of mutations was brought forth by :


473) Represented below is the inheritance pattern of a certain type of trait in humans. Which one of the following conditions could be an example of this pattern ?


474) When both alleles of a pair are fully expressed in a heterozygote, they are called


475) Depending upon the distance between any two genes which is inversely proportional to the strength of linkage, cross over will vary from


476) Which is correct for Turner's syndrome ?


477) Among the seven pairs of contrasting traits in pea plant as studied by Mendel, the number of traits related to flower pod and seed respectively were


478) Some of the dominant traits studied by Mendel were


479) The colour based contrasting traits in seven contrasting pairs, studied by Mendel in pea plant were


480) A mechanism that can cause a gene to move from linkage group to another is


481) A normal visioned man whose father was colour blind, marries a woman whose father was also colour blind. They have their first child as a daughter, what are the chances that this child would be colour blind?


482) Theoretically, the modified allele could be responsible for the production of
I. the normal/less efficient enzyme
II. a non-functional enzyme
III. no enzyme at all


483) Go through the following statements in respect of pea.
I. A single gene product may produce more than one effect.
II. BB produces round seed with large sized starch grain.
III. Bb produces wrinkled seed with small sized grain.
IV. Bb produces round seeds with larged grain.
V. Heterozygote Bb produces round seed with intermediate sized starch grain.
VI. Allele B is dominant over allele b in respect of seed shape but their relation is incomplete dominance in respect of starch grain size.
How many of the above statements are correct?


484) A gene may have many alleles, but each individual has only two alleles because


485) Mendel's laws are explained by


486) A limitation of pedigree analysis of human trait is


487) The ___________ rule of probability is useful in calculating the risk that certain individuals will inherit a particular genotype.


488) A ratio of 12 : 3 : 1 is most characteristic of a cross involving __________ .


489) A mother who is blood type AB has a child who is also AB. A potential father is blood type O. A well informed geneticist concludes that ____________ .


490) Why didn't Mendel find linkage?


491) Genes A and B are farther apart than are genes A and C, and all three are linked. What CANNOT be concluded?


492) The incorrect statement with regard to Haemophilia is


493) If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?


494) Which of the following statements is not true of two genes that show 50% recombination frequency?


495) If two persons with 'AB' blood group marry and have sufficient large number of children, these children could be calssified as 'A' blood group. 'AB' blood group : 'B' blood group in 1 : 2 : 1 ratio. Modern technique of protein electroporesis reveals presence of both 'A' and 'B' type proteins 'AB' blood group individuals. This is an example of


496) Both husband and wife have normalvision though their fathers were colour blind and mother without any allele for colour blindness. The probability of their daughters becoming colour blind is


497) For finding the different types of gametes produced by genotype AaBb. It should be crossed with genotype


498) What should be the composition of gametes?


499) Anish is having colour blindness and married to Sheela, who is not colour blind. What is the chance that their son will have the disease?


500) A man whose father was colour blind marries a woman who had a colour blind mother and normal father. What percentage of male children of this couple will be colour blind?


501) Fruit colour in squash is an example of


502) A human female with Turner's syndrome


503) The frequency of crossing over occurring between two genes located on the same chromosome depends on


504) Anish is having colour blindness and married to Sheela, who is not colour blind. What is the chance that their son will have the disease?


505) In garden pea, round shape of seeds is dominant over wrinkled shape. A pea plant heterozygous for round shape of seed is selfed and 1600 seeds produced during the cross are subsequently germinated. How many seedling would have the parental phenotype?


506) In order to lessen the suffering of phenylketonurics their diet should have


507) Which of the following sets of syndromes show 47 chromosomes in their genetic make up?


508) Genetic disorder haemophilia is characterized by excessive loss of blood. Which of the following statement is not true in relation to this disease?


509) Phenotype of an individual is reflected by the contribution of each allele, i.e., the effect of each allele is additive in/for


510) How many of the given traits of garden pea can express itself in heterozygous condition?
Green seed, inflated pod, Axial flower position, Dwarf plant height, Yellow pod colour, Round seed shape.


511) In the first step of monohybrid cross experiment, Mendel selected pea plants which were


512) Epicanthal skin fold and simian crease are characteristics of


513) A woman with blood group 'O' has a child with blood group 'O'. If she claims a friend of hers with blood group 'A' as father of the child, the genotype of the father should be


514) Test cross involves


515) Distance between the genes and percentage of recombination show


516) Three copies chromosome - 21 in a child with Downs syndrome have been analysed using molecular biology technology to detect any possible DNA polymorphism with reference to different alleles located on chromosome - 21. Results showed that out of 3 copies 2 of the chromosomes of the child contain the same alleles as one of the mothers alleles. Based on this when did the non-disjunction event most likely occur?


517) A set of genes will be in a complete linkage when the progeny phenotypes for parental (P) and recombinant (R) types are


518) Which one of the following statements is relevant to sex linked characters?


519) Which of the following is/are correct the inheritance of genes involved in human 'ABO' blood grouping?
I. It is inherited by complete dominant allele.
II. It is inherited by complete recessive allele.
III. It is inherited by co-dominant allele.
IV. It is inherited by single gene with more than two alleles.


520) A species has 2n = 16 chromosomes. How many chromosomes will be found per cell in each of the following mutant species?
I. Monosomic
II. Autotriploid
III. Trisomic
IV. Double monosomic
V. Nullisomic.
The correct sequence of chromosomes for (I to V) are


521) A point mutation that changes a codon specifying an amino acid into a stop codon is called a


522) What is the minimum number of base substitutions required to change the nucleotide sequence of the HbA (normal) allele to the HbS (sickle cell) allele?


523) How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?


524) Multiple alleles are present


525) The movement of a gene from one linkage group to another is called


526) Alleles are


527) An abnormal human baby with 'XXX' sex chromosomes was born due to


528) The term "linkage" was coined by


529) A gene showing codominance has


530) In his classic experiments on pea plants, Mendel did not use


531) A pleiotropic gene


532) A colour blind man marries a woman with normal sight who has no history of colour blindness in her family. What is the probability of their grandson being colour blind?


533) Mr. Arora is hetrozygous for three autosomal gene M, N and T and homozygous recessive for 4th autosomal gene P. They have gene for colour blindness (c) on X chromosome. What will be the probability for sperm to carry mNTpc condition.


534) Colour blindness in humans is due to a sex-linked recessive gene. A survey of 500 men from a local recessive revealed that 20 were colour blind. What percentage of the female in this population would be expected to be normal?


535) A x-linked gene has 15 alleles then what will be possible genotypes in population


536) The sequence of which chromosome no was completed in May 2006.


537) If both parents are carrier for albinism and having blood group AB, what are the chances of offspring having normal pigmentation and AB blood group.


538) How many of the following are Medelian disorders?
Haemophilia, Cystic fibrosis, sickle cell anaemia, colour blindness, phenyl ketonuira, Thalesemia.


539) Mendelian disorders are mainly determined by


540) In which of the following organism, genes are found in original arrangement, no recombination.


541) Gene A and B are linked and 12 map units apart. A heterozygous individual, whose parents were Aabb and aaBB, would be expected to produce gamete in the following frequencies


542) In a completely linked trihybrid test cross, phenotypic ratio will be


543) In Lathyrus odoratus gene A and B are essential in dominant form to produce purple colour then which of the following cross produce only coloured offspring.
I. Aa Bb x aa bb
II. aa BB x AA bb
III. AA BB x aa bb
IV. aa BB x aa Bb


544) Genes A and B are necessary for normal hearing, what is the possible genotype of normal child of deaf mother and deaf father


545) Absence of one sex-chromosome causes


546) First husband of Asha has ABO blood type A and their child has type O. She remarried and her husband has ABO blood type B and their child has type AB. What is the ABO genotype of Asha and also name her blood type.


547) Mendel found that the reciprocal crosses fielded identical results from that he concluded that


548) Haemophilia is a


549) A diseased man marries a normal woman. They get three daughter and five sons. All the daughters were diseased and sons were normal. The gene of this disease is?


550) Which of the following most appropriately describes haemophilia?


551) Pcik out the correct statements:
(a) Haemophilia is a sex-linked recessie disease
(b) Down's syndorme is due to aneuploidy
(c) Phenylketonuria is an autosomal recessive gene disorder.
(d) Sickle cell anaemia is a X-linked recessive gene disorder.


552) A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of chromosomes as compared to other dividing cells. This would result in


553) If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is


554) In metamale Drosophila, chromosome combination is


555) Which one is sex-linked disease in man?


556) Marriage between persons having AB blood groups would produce


557) When a colour blind female offspring is born?


558) Which of the following options correctly describes the similarity and the difference between chromosomal aberrations and gene mutations?


559) The gene for ABO blood group is located on


560) Down syndrome is one of the most common chromosome abnormalities in humans. It occurs


561) A haemophilic woman marries a normal man, then


562) Disorder inherited as Mendel’s law of inheritance called


563) Chromosome is made up of


564) Select the incorrect statemant from the following.


565) A pure tall and a pure dwarf plant were crossed to produced offsprings. Offsprings were self crossed, then
find out the ratio between true breeding tall to true breeding dwarf?


566) A self-fertilizing trihybrid plant forms


567) Genotype is the


568) Failure of cytokinesis after …A… stage of cell division results in an increase in a whole set of chromosomes
in an organism called …B…


569) In previous question find out total seeds (plants) having round seed texture


570) The ratio 1 : 1 : 1 : 1 is obtained from a cross between the parents


571) Which of the following terms represent a pair of contrasting characters?


572) Harmful mutation does not get eliminated from the gene pool because they are mainly


573) Incomplete linkage is …A… . Complete linkage is …B… . Choose correct option for A and B


574) In gynandromorphs,


575) Example of interagenic gene interaction is/are


576) If a cross between two individuals produces offspringe with 50% dominant character (A) and 50%
recessive character (a),then the genotypes of parents are


577) Which is correct about traits choosen by Mendel for his experiment on pea plant?


578) Codominance is found in


579) During Mendel’s investigation, it was first time that …A… and …B… were applied in biology. Here A and B
refers to


580) The chromosomal denotation for heterogametic female and homogametic male are


581) The best method to determine the homozygosity and heterozygosity of an individual is


582) A medical technician, while observing a human blood smear under the microscope notes the presence of a
Barr body close to the nuclear membrane in the WBC. This indicates that the person under investigation is
a


583) In Turner’s syndrome


584) The most likely reason for the development of resistance against pesticides in insect damaging a crop is


585) Lampbrush chromosomes sre seen in


586) Examples of dissimilar sex chromosomes are given below
I. XX – XY ⇒ I
II. XX – XO ⇒ II
I and II in the above statement can be


587) Mutations, which alter nucleotide sequence within a gene are


588) Mendel’s law were true for situation in which


589) Blood group-O has


590) Wilson detected the colour blindness disease in


591) A women with albinic father marries an albinic man.the proportion of her progeny is


592) When one sex chromosome is lacking in female and males are homogametic, in that condition, the sex
chromosomal representation is


593) Some individuals with blood group –A may inherit the genes for blonde hair, while other individuals with
blood group – A may the gene for brown hair. This can be best explained by the principle of


594) In bugs and cockroaches, the sex determination takes place by


595) The two …A… separate and pass into two daughter nuclei and cells during mitosis. Similarly, each …B…
replicates, with one pair passing into each daughter cell during mitosis. This maintains the similar …C… of
all the cells.
Find out correct option for A, B and C


596) The shape of chromosome is determined by


597) Mendel was a


598) Who clearly proved and define linkage?


599) Improvement of human race through hereditary qualities is called


600) When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the
resulting seed is


601) Colour blindness is


602) A condition, where a certain gene is present in only a single copy in a diploid cell, is called


603) If the blood group of a child is A and of mother is B, then the genotype of mother and father may be


604) Which amino acids are present in histones?


605) Monosomic trisomy are represented as


606) Which is a sex-influenced disease?


607) Thalassaemia is


608) Mutation is phenomena which results in alternation of


609) A man with normal vision whose father was colourblind marries with women whose father was also
colourblind. Suppose their first child is daughter then what are the chances of this child to be colourblind?


610) Gamete mother cells of the chromosome 44 + XY suffers from non-disjunction at first meiotic division.
Which of the following set of gametes would result?


611) Law of Mendel, which is not completely applicable is?


612) Low pitched voice, beared and moustaches, belong to the


613) Multiple allele can be manifested only when there is the study of


614) Nicotiana sylvestris flowers only during long days and N. tobaccum flowers only during short days, if
raised in the laboratory under different photoperiods, they can be induced to flower at the same time and
can be cross fertilized to produce self-fertile offspring. What is the best reason for considering N. sylvestris
and N. tobaccum to be separate species?


615) Down’s syndrome and Turner’s syndrome occur in human beings due to


616) What are all the chances of colourblind daughters of a normal man marrying normal women whose father
was colourblind?


617) In males, pattern baldness is related to both autosomal genes as well as excessive secretion of


618) Which of these is not a Mendelian disorder?


619) Which of the following is not true of haemophilia?


620) If heterozygous dominant (tT) crossed with homozygous dwarf plant, then the percentage of progeny
having dwarf character is


621) Mutations are generally induced by means of


622) A hereditary, disease, which is never passed on from father to son is


623) A person having 45 chromosomes and Y-chromosome absent. Is suffering from


624) Linkage and crossing over are


625) The modern concept of gene is


626) Females in haplodiploidy sex determination are


627) Using imprints from a plate with complete medium and carrying bacterial colonies, you can select
streptomycin resistant mutants and prove that such mutations do not originate as adaptation. These
imprints need to be used


628) Phenylketonuria, Huntington’s disease and sickle cell anaemia are caused respectively due to disorders
associated with


629) The arrangement of genes on chromosome is


630) Which of the following matches correctly?


631) The longest chromosomes is seen in


632) Mendel observed that ….. generation shows always phenotype of dominant parent


633) ...A… genes are those which occurs on the same chromosome and …B… genes are those, which are present
on different chromosome.
Choose correct choice for A and B


634) Allelic sequence variations where more than one variant (allele) at a locus in a human population with a
frequency greater than 0.01 is refered to as


635) The possibility of a female becoming a haemophilia is …A… rare because mother of such a female has to be
at least …B… and the father should be …C…
Choose the correct option for A, B and C


636) The most popularly known blood grouping is the ABO grouping. It is named ABO and not ABC, because ‘O’
in it refers to having


637) Telomere repetitive DNA sequences control the function of eukaryotic chromosomes because they


638) Genotypic and phenotypic ratios remains the same in


639) Mendelian disorder may be of


640) Sickle –cell anaemia has not been eliminated from the African population because it


641) A condition characterized by not having an exact number of chromosomes in a multiple of haploid set is called


642) Chromosomes are made up of


643) In pedigree analysis, the square, blackened and horizontal lines represents


644) Mr. Sidd is suffering from hypertrichosis and phenylketonuria. His father is heterozygous for
phenylketonuria. The probability of Sidd’s sperm having one recessive autosomal allele and holandric
gene is


645) In which one of the following, complementary gene interaction rato of 9 : 7 is observed?


646) Starch synthesis gene in pea plant is the example of


647) In Drosophila , the sex is determined by


648) Sexual reproducation leads to


649) Husband has blood group-A and wife has blood group-B. What is the blood group of children?


650) Haemophilia, a X-linked recessive disease is caused due to deficiency of


651) All of this obeys Mendel’s laws except


652) Who was fly men of genetics?


653) Mendel’s contribution for genetic inheritance was


654) Baldness is more common in men than in woman. It could be explained on the basis that


655) How many pairs of contrasting characters in pea pod were chosen by Mendel?


656) A mutagen pollutant is


657) Both chromosome and gene (Mendelian factors) whether dominant or recessive are transmitted from
generation to generation in which form


658) Pedigree analysis is very important in human beings because


659) Genes when present in homozygous condition results in non – viable progeny, the factor responsible for
such conditions are


660) Turner’s syndrome caused due to the absence of


661) The recessive genes located on X-chromosome in humans are always


662) Strength of the linkage between the two genes is


663) Fruitfly is excellent model for genetics because of
I. Small life cycle (two week)
II. Can be feed on simple synthesis medium
III. Single mating produce large number of progeny
IV. Clear differentiation of sexes
V. Many heredity variation can be seen with low power microscopes
Choose the correct option


664) When both parents are of blood type AB, they can have children with


665) Test cross is


666) The phenomenon of a single gene regulating several phenotypes is called


667) If two pea plants having red (dominant) coloured flowers with unknown genotypes are crossed, 75% of
the flowers with unknown genotypes are crossed, 75% of the flowers are red and 25% are white. The genotypic constitution of the parents having red coloured flowers will be


668) A woman has a haemophilic son and three normal children. Her genotype and that of her husband with
respect to this gene would be


669) Night blindness is


670) Who argued that pairing and separation of chromosomes would lead to the segregation of a pair of factor
they carried?


671) Sex chromosomes of male are


672) Trisomy of which chromosome is involved in Down’s syndrome?


673) Which of the following symbols are used for representing chromosome of birds?


674) Sudden and heritable change in a character of an organism is called


675) Heterozygous purple flower is crossed with recessive white flower. The progeny has the ratio


676) The Mendel crossed true breeding tall and dwarf plant varieties in his experiment. The tall character was
dominant and recessive character was dwarf. The recessive character was appeared in


677) Night blindness can be corrected by giving vitamin- …A… but colour blindness can’t be cured because it is
…B… disease.
Choose the correct option for A and B


678) Heredity is


679) Which of these statements about Huntington’s disease is true?


680) Centromere is required for


681) Which of the following condition in humans is correctly matched with its chromosomal
abnormality/linkage?


682) Rrrr progeny : Red (dominant) flowered heterozygous crossed with white flower


683) A hereditary disease which is never passed on form father to son is


684) A man with blood group-B marries a woman with blood-A and their first child is having blood group-B.
What is the genotype of child?


685) Linked gene are present on


686) The structure that become double in synthesis phase of cell division is/are


687) Genetics is the branch of biology which deals with


688) Giant chromosomes are found inside


689) Who is known as father of physiological genetics or father of biochemical genetics?


690) The graphical representation to calculate the probability of all possible genotypes of offspring in a genetic
cross, is called


691) Rh factor can produce disease


692) To determine heterozygousity of a cross, one has to perform


693) Which of the following type of mutation involves the reverse order of genes in a chromosome?


694) The chromosomal number in the meiocytes of housefly is


695) The alternate forms of a gene is called


696) Haemophilia is related to


697) Identify a Mendelian disorder from the following.


698) The term ‘Genetics’ was proposed by


699) Sex chromosomes are also known as


700) In a family father had a trait but mother did not. All their sons and daughter had this trait. The same trait
was found in some grand daughters, through daughter were married to the normal persons.
Choose the correct pedigree chart for the condition


701) If genes of an allelic pair are not-same. This condition is called


702) Which type of pollination method was adopted by Mendel in his experiment?


703) Select the correct statement from the ones given below with respect to dihybrid cross.


704) Chromosomal abbreviation commonly found in the


705) In short horned cattle, genes for red( R) and white( r) coat colour occur. Cross between red (RR) and
white (rr) produced (Rr) roan. This is an example of


706) Female is haemophilic definitely if


707) Polyploidy leads to rapid formation of new species because of


708) Law of segregation is also called law of


709) Test cross is a cross between


710) XX and XY chromosomal sex determination, females are


711) Heterogametic male condition does not occur in


712) The genotype of a plant showing the dominant phenotype can by


713) If a man who is colourblind marries a women, who is pure normal for colour vision, the chances of their
sons have colour blindness is


714) Broadly the genetic disorders may be classified in …A… group Mendelian disorder and …B… disorders.
Mendelian disorder are mainly determined by …C… in single gene.
Choose the correct option for A, B and C


715) …A… individual show …B… phenotype but they are the …C… of the disease as there is 50% probability of
transmission of mutant gene to its progeny
Choose the correct option for A, B and C


716) If male is TT and female is tt than they contribute pollen and egg respectively with


717) Number of linkage group in Pisum sativum is


718) BB = for black colour alleles
bb = for brown colour alleles
Offspring of a cross between a black mouse and brown mouse allowed to interbreed than find out the
percentage of black coat in them


719) The mutant haemoglobin molecule undergoes polymerization under low oxygen tension causing the
change in the shape of RBC from biconcave to elongated structure. This property of RBC is found in


720) XO type of sex determination is seen in


721) Chimera is produced due to


722) How many pairs of true breeding varieties were selected by Mendel for his experiment on pea plant


723) Syndrome stands for


724) Parents with blood group-A and AB will not produce offspring with blood group


725) The genetic deficiency of ADH-receptor leads to


726) TtRr represents (heterozygous tall, heterozygous pink). If this plant is self crossed then
(T-dominant, t-recessive, R-dominant, r-recessive)
I. 25% plant have red flower
II. 25% plant have white flower
III. 50% plant have pink flower
IV. 50% plant are tall
Choose the correct option


727) Which of the following observation made Mendel in refutation of the blending theory of inheritance?


728) Mutations are generally


729) The ‘Cri-du-chat’ syndrome is caused by the change in chromosome structure involving


730) Pedigree analysis indicated that Mendel’s principal are also applicable to …A… genetics with some
modifications find out like …B… inheritance, sex linked inheritance and others.
Choose the correct option for A and B


731) Genes for cytoplasmic male sterility in plants are generally located in


732) A distinct mechanism that usually involves a short segment of DNA with remarkable capacity to move
from one location in a chromosome to another is called


733) The individual from which a pedigree analysis initiated is called


734) Plant which used by Hugo de Vries for mutation experiment was


735) A person is suffering from disease phenylketonuria, which is an autosomal recessive disease. Which of
these is lacking in the person?


736) Haemophilia in man is due to


737) When a dihybrid cross is fit into a Punnett square with 16 boxes, the maximum number of different
phenotypes available, are


738) 2n-2 is known as


739) A man and a woman, who do not show any apparent sign of a certain inherited disease, have seven
children (two daughter and five sons). Three of the sons suffer from the given disease but none of the
daughters are affected. Which of the following mode of inheritance do you suggest for this disease?


740) Colourblindness is caused due to


741) Which principle/law has been called the 2nd law of inheritance?


742) Mendel’s experiment were based on hybridization between two plants differing in


743) Alleles can be similar as in the case of …A… like ...B… or can be dissimilar as in the case of …C… like …D…
Choose the correct option for A,B,C and D


744) The Barr body is observed in


745) If a colourblind woman marries a normal visioned man, their sons will be


746) Barr body is produced due to partial inactivation of one X-chromosome in female. This is called


747) Analysis of traits of several generation of a family in the form of diagram is called


748) Among the following which one is the mutagenic agent?


749) Frameshift mutation and base pair substitution changes the


750) A women with blood-O has a child with blood group-O. She claims that a man with blood group-A is the
father of her child. What would be the genotype of the father, if her claim is right?


751) The terminal end of chromosomes is called


752) Mendel conducted experiments for


753) Cross between unrelated group of organisms, is called


754) If AAbb × aaBB, then phenotypic ratio of its progeny will be


755) I. Short statured with small round head
II. Furrowed tongue and partially opened mouth
III. Palm is broad with characteristic palm crease
IV. Slow physical, psycomotor and mental development
These are the characters of


756) Which of the following statements are false?
I. A Dominant allele determines the phenotype when paired with a recessive allele
II. A recessive allele is weaker than a dominant allele
III. A recessive allele do not shows its effects when paired with a dominant allele
IV. A dominant allele is always better for an organism


757) Phenotype of an organism is the result of


758) Which of the following is not a hereditary disease?


759) Gynaecomastia is a common feature seen in


760) Linked gene is related to …A… and unlinked gene is related to …B…
Choose correct option for A and B


761) The linkage map of X-chromosomes of fruit fly has 66 units, with yellow body gene (y) at one end and
bobbed hair (b) gene at the other end. The recombination frequency between these two genes (y and b)
should be


762) In man, which of the following genotypes and phenotypes may be the correct result of aneuploidy in sex
chromosomes?


763) Experimental evidence of chromosomal theory of inheritance was given by


764) Theoretically in incomplete dominance one allele function as normal, while another allele may function as


765) In a family, man have blood group-A and women have blood group-B. Blood group of their children will be


766) Principle or laws of inheritance were enunciated by


767) Mendel’s law was explained by


768) Which statement about Mendel is true?


769) The loss of chromosomal segment is due to


770) The chromosomal condition in Turner’s syndrome is


771) If a child is of O blood group and his father is of B blood group, the genotype of father is


772) Work of Beadle and Tatum on Neurospora crassa proved that


773) Cytoplasmic inheritance always shows


774) Type of gamete participating in selfing of members in monohybrid cross are of


775) In sickle-cell anaemia, GAG is replaced by


776) Genes, when close together on a chromosome, are known as


777) Hugo de Vries is famous for


778) Jumping genes in maize were discovered by


779) Chromosomal theory of inheritance was proposed by


780) In sex linkage, the speciality is


781) Mother = A blood group
Father = AB blood group
The child will not have


782) The chromosome constitution 2n-2 of an organism represents


783) Phenylalanine does not changed to tyrosine. This condition is seen in


784) When the chromosome number of a given organism has one additional chromosome in one of the
homologous pairs, the addition is known as


785) What type of gametes will form by genotype rr Yy?


786) The term ‘genetics’ was introduced in


787) Mutant genes that give slightly modified phenotypes are


788) Which of the following is an example of sex-linked disease?


789) Mutations can be induced with


790) Which of the following is an inherited disorder?


791) The title of Mendel’s paper, while presenting at Brunn Natural History Society in 1865 was


792) XO chromosomal abnormality in humans causes


793) Milk secretion and baldness, both the traits belongs to


794) The daughter born to haemophilic father and normal mother could be


795) Blood grouping is the example of


796) A true breeding plant producing red flowers is crossed with a pure plant producing white flowers. Allele
for red colour of flower is dominant. After selfing the plants of first filial generation, the proportion of
plants producing white flowers in the progeny would be


797) …A… is sex linked recessive disease. Which shows its transmission from …B… female to …C… progeny.
Choose the correct option for A, B and C


798) Crossing over is advantageous because it brings about


799) Father of ‘genetics’ is


800) The recessive gene that always produces its effect, is


801) When different alleles of the same gene are present on an individual, the individual is a


802) Sex linked traits are the traits determined by


803) Number of Barr body in XXXY is


804) 21 trisomy in humans causes


805) Paternal baldness, moustaches and beard in human males are example of


806) A normal women whose father was colourblind, is married to a normal man. The sons would be


807) The female children of haemophilic father and carrier mother are


808) How many conditions exhibit in dissimilar sex chromosomes?


809) Number of chromosomes in Down’s syndrome are


810) Which phenomena leads to the variation in DNA


811) External morphology or appearance or descriptive term of an genotype is called


812) In which of the following, there is no defect in the sex chromosome?


813) The traits which are not expressed due to a particular gene but are expressed by products of sex hormones
are


814) Choose the correct option for the chromosomal disorders
I. Colour blindness
II. Down’s syndrome
III. Phenylketoria
IV. Turner’s syndrome
V. Thalassaemia


815) Who postulated the mutation theory?


816) Choose the chemical used in artificial polyploidy


817) Linkage groups are always present on the


818) Emasculation is the removal of


819) The genes, which remain confined to differential region of Y-chromosome, are


820) First time who used the term frequency of recombination?


821) Mutation cannot change


822) Mendel does not get linkage due to


823) Frameshift mutation arises due to


824) Genes A, B and C are linked. Genes A and B are more close than A and C. Find out the correct option for the
given statements
I. A might be before B and C
II. B might be between A and C
III. C might be between A and B
IV. More crosses has occurred between A and C than A and B


825) In previous question find out the ratio between round and wrinkled seed texture


826) Which of the following blood groups’ person can not donate blood to other?


827) Which of the following is not related to sex chromosome X or Y?


828) Inheritance of characters not located in the gene but the young one resembling only the female part is due
to


829) Which of the following pairs of features is a good example of polygenic inheritance?


830) Incomplete dominance is shown by


831) Which of the following genes show the hetertozygous condition?


832) Rrrr (progeny): Red (dominant) flowers (heterozygous) were crossed with white flower. The result will
be


833) Which of the following has the least number of chromosomes?


834) The chemical nature of chromatin is as follows


835) Mendel observed that certain character did not assort independently. Later, scientist found that this is due
to


836) Mendel investigated characters in garden pea plant that were manifested in two ….. trait


837) Phenylketonuria disease is a


838) The literal meaning of chromosome is


839) The offspring produced from a marriage have only O or A blood groups. Which of the following genotypes
would be, the possible genotypes of the parents?


840) The lowest number of chromosomes is found, in which of the following?


841) The genes for seven characters of pea plant that were considered in Mendel hybridisation experiment are
present on


842) Identify the wrong statement.


843) Which of these is a dominant factor?


844) In thalassaemia, the affected chain of a haemoglobin is


845) Sex chromosomes in male of silkworm is


846) During …A… both members of chromosome pair as well as …B… separate and pass to different gametes.
Choose the correct option for A and B


847) Genetic map is one that


848) Human females have


849) The progenies are found to be male sterile after crossing two plants. This is due to some genes, which are
present in


850) Mutation may results in the


851) A cross in which parents differ in a single pair of contrasting character is callled


852) Calvin bridges demonstrated sex determining factor is the ratio of number of


853) Ratio observed in dihybrid cross (phenotypically)


854) Trisomy stands for


855) A couple whose sons are colourblind with AB blood group, identify the parents from the following


856) Which of the following chromosomal mutation are most likely to take place when homologous
chromosomes are undergoing synapsis?


857) Mendel could not find out linkage because
I. some genes are linked but they are too far apart for crossing over to be distinguished from independent
assortment
II. linked genes, were never tested for the same time in same cross
III. all seven genes, were present on the same chromosomes
IV. all seven genes were present on 4 chromosome but they were present far apart
Find out the correct option


858) Haemophilia is also called


859) The genes located in the same chromosome do not separate and are inherited together over its
generations due to the phenomenon of


860) Universal donor is


861) Persons with Klinefelter’s syndrome have chromosomes


862) Sex- limited and sex- linked genes are located on


863) Point mutation involves


864) A person with type A blood group may safely receive a transfusion of


865) In which cross will you get most pink flowers?


866) Which one of the following characters studied by Mendel in garden pea was found to be dominant?


867) Mendel’s experimental material was


868) Which of the following is not considered as mutagen?


869) The physical expression or appearance of a character is called as


870) Carrier organism refers to an individual, which carries a


871) In amniocentesis of a pregnant woman, it is found that the embryo contains both, Barr body and F-body.
The syndrome likely to be associated with the embryo is


872) In the previous question, find out the chances of fifth child to be albino


873) Three children in a family have blood types O, AB and B respectively. What are the genotypes of their
parents?


874) The chromosomal arrangement results in


875) The specific pair of chromosomes which determine the sex of the individual called


876) During his experiments, Mendel used the term factor for


877) Albinism is caused by the deficiency of


878) The ABO blood grouping in human beings is an example for
I.Dominance
II.Incomplete dominance
III.Codominance
IV.Multiple alleles


879) Diploid cells have


880) Single gene can produce more than one effect. Like starch synthesis in pea plant. It has two alleles (B and
b) for starch synthesis the phenotypes of which are also given below
B B, b b, B b
I. BB – round seed, large starch synthesis
II. bb – wrinkle seed, less starch synthesis
III. Bb – intermediate size seed, intermediate less starch synthesis
Choose the correct option


881) After examining the blood groups of husband and wife, the doctor advised them not to have more than one
child, the blood group of the couple are likely to be


882) Which of the following is not a correct match?


883) In law of independent assortment. How many factors are involved? (for a dihybrid cross)


884) Mother B homozygous, father A unknown, therefore, possible blood group in progeny is


885) When released from ovary, human egg contain


886) The tendency of offsprings to differ from their parents is called


887) The gene, which controls many characters, is called


888) Which of the following statement is/are correct regarding law of segregation?


889) Which of the following discoveries resulted in a Nobel Prize?


890) When alleles of two contrasting characters are present together, one of the character expresses itself
during the cross while the other remains hidden. This is the


891) In which phase of meiosis-I the two chromosome can align at the metaphase plate independently of each
other


892) When a mutation is limited to the substitution of one nucleotide for another, it is called


893) Types of genotype observed in a dihybrid cross are


894) Which cross was used to study the independent assortment?


895) Which of the following statements about mutation are true?
I. Mutations are the source of new alleles for genes
II. Organisms are able to create mutations to meat their specific needs
III. Mutations are random events and can happen in any cell at any time
IV. Most mutations tend to be harmful or have no effect on an organisms


896) Centromere is also called


897) Which of the following statements are false?
I. Specific mutations are acquired because they are needed
II. Recessive alleles follows different laws of inheritance than dominant alleles do
III. Offspring get two copies of each gene from each parent
IV. Gametes fuses without regard to which alleles they carry


898) Which contributed to Mendel’s success?
I. Selection of pea plant
II. Knowledge of history
III. One character at one time
IV. His statistical knowledge
Choose the correct option


899) In XX and XO chromosomal sex determination there is absence of one chromosome in


900) A child of blood group-O cannot have parents of blood groups


901) Rh factor is present in


902) Which of the following condition is called monosomic?


903) A man of blood group–A marries woman of blood group-AB, which type of progeny would indicate that
man is heterozygous?


904) The children of a haemophilic man and a normal women are


905) In man, four phenotypes of blood groups are due to the presence of antigen-A and antigen-B on the RBC.
The chromosome that has the gene to control these antigens is


906) More men suffer from colourblindness than women because


907) ‘Cri-du–chat’ syndrome in humans is caused by the


908) Which of the following symbols and its representation, used in human pedigree analysis is correct?


909) Ischihara chart is used to detect


910) Genes exibiting multiple effects are known as


911) A person with blood group –AB has


912) Excessive growth of hair on the pinna is a feature found only in males because


913) Incomplete dominance is different from complete dominance in having


914) A true breeding plant producing red flowers is crossed with a pure plant producing white flowers. Allele
for red colour of flower is dominant. After selfing the plants of first filial generation, the proportion of
plants producing white flowers in the progeny would be


915) Studies of human sex-linked trait shows that


916) If a cross between two individuals produces offspringe with 50% dominant character (A) and 50%
recessive character (a),then the genotypes of parents are


917) Mendel choose the garden pea plant for his experiment and his findings were based on


918) One of the following is not the type of blood groups or blood factors.


919) Is it possible that same genotype have different phenotype?


920) In a cross between individuals with genotypes Tt Rr, if the resulting number of offsprings is 16, then
identify the number of genotypes with TtRr and TtRR amongst them.


921) Which of the following genotypes does not produce any sugar polymer on the surface of the RBC?


922) The diagrammatic representation of the chromosomes of an individual is called


923) In Mirabilis, a hybrid for red (RR) and white (rr) flower produces pink (Rr) flower. A plant with pink
flower is crossed with white flower, the expected phenotypic ratio is


924) A marriage between normal visioned man and colourblind woman will produce, which of the following
types of offsprings?


925) I. Myotonic dystrophy is an autosomal dominant trait
II. Sickle-cell anaemia is an autosomal recessive trait
III. Failure of segregation of alleles results in chromosomal loss
IV. Failure of segregation of allele result in chromosomal gain
V. Cystic fibrosis is a Mendelian disorder
Correct statements are


926) Haemophilia is more commonly seen in human males than in human females because


927) Which one of the following was the rediscoverer of Mendel’s work?


928) Which of the following abnormalities, results from an unnatural presence of a Barr body?


929) When normal and mutant alleles are present on opposite chromosomes of homologous pair, the
heterozygotes are called as


930) The types of gametes produced by a heterozygous allelic pair is/are


931) Prokaryotic genetic system has


932) A chromosome in which the centromere is situated close to its end so that one arm is very short and the
other very long is


933) Write the genotype of the previous questions


934) Sickle cell anaemia is


935) Improvement of human race through hereditary qualities is called


936) …A… gene produces all gametes that are similar, while a ….B… produces two kinds of gametes each having
one allele with equal proportion
Choose the correct option for A and B


937) When the number of recombinant progeny is usually less than the number expected in independent
assortment it is called


938) The enzyme missing in phenylketonuria is


939) Gene is


940) The telomeres of eukaryotic chromosomes consist of short sequences of


941) In Mendelian dihybrid cross when heterozygous Round Yellow are self crossed. Round Green offsprings
are represented by the genotype


942) Mendel’s principle of segregation means that the germ cells always receive


943) In Melandrium, the sex determination type is


944) The effect of todays radioactive fall out will probably be more harmful to children of future generation
than to children now living because


945) Select the statement which is not correct.


946) Linkage was first suggested by


947) X-linked recessive gene is


948) Gene for colour blindness is located on


949) The ABO blood group are controlled by


950) When an animal has both the characters of male and female, it is called


951) Point mutation arises due to change in


952) colour blindness is more observed in …….humans


953) Genetic or chromosomal symbol used for the person who is having sickle-cell anaemia is


954) Which of the following is true regarding human genetics?


955) Foetal sex is determined by examining cells from amniotic fluid looking for


956) What is genotypic ratio in a dihybrid cross?


957) The law of segregation of characters is also called the law of purity of gametes because


958) Four children belonging to the same parents have the following blood groups A, A, AB and O. Hence, the
genotypes of the parents are


959) Mendel work later formulated into laws of
I. Linkage
II. Segregation
III. Incomplete dominance
IV. Independent assortment
Choose the correct option


960) Barr body is associated with


961) A man can inherit his X-chromosome from his


962) The types of gametes formed by the genotype Rr Yy are


963) Mating of an organism to a double recessive in order to determine whether it is homozygous or
heterozygous for a character under consideration, is called


964) Polyploidy means occurrence of


965) L –shaped chromosomes are also called


966) A polygenic trait is controlled by 3 genes A, B and C. In a cross AaBbCc× AaBbCc, the phenotypic ratio of
the offsprings was observed as 1 : 6 : x : 20 : x : 6 : 1.
What is the possible value of x?


967) Chromosomal mutations occurs due to
I. Deletion II. Duplication
III. Translocation IV. Inversion
Choose the correct option


968) The allele which expresses itself in both homozygous and heterozygous condition is called


969) Equatorial division and reductional division takes place in which types of cell division


970) Monohybrid test cross ratio is


971) Who gave the term ‘genetics’?


972) In which of the following disorders, blood has a defective haemoglobin?


973) In sickle cell anaemia, the glutamic acid is replaced by


974) Which of the following cannot be explained on the basis of Mendel’s Law of Dominance?


975) Find out the percentage of dominant phenotype in cross between Pp and Pp. P-dominant, p-recessive


976) Gametes produced by a homozygous individual is/are of …. types


977) What will be the gametic chromosomes number of a cell, if somatic cell have 40 chromosomes?


978) Human female possesses 44+XX chromosomes. The secondary oocyte shall have


979) Select the correct statement from the ones given below with respect to dihybrid cross.


980) Test cross is when


981) Euploidy is best explained by


982) In which year Mendel’s work rediscovered


983) Which of the following diseases is governed by pleiotropic genes?


984) Heterochromatin remains condensed in which part of chromosome?


985) Which have great importance in genetics?


986) Number of Barr bodies in XXXXY is


987) Dihybrid ratio of the linked gene is


988) Polyploidy can be induced by the application of


989) Which of the following, can be used to describe the alleles correctly?


990) Which of the following animals is mostly used in genetics experiments?


991) Which of the following diseases results from the genetic inability to synthesize a single enzyme?


992) Balbiani rings are the structural features of


993) Sometimes, there are more than two alleles for a given chromosome locus. In this case, a trait is controlled
by


994) In haplodiploidy determination of sex, males is


995) When mutation is confined to only one substitution, it is called


996) Letter symbol refers to the dominant factors give a …A… or upper case latter of the alphabet. A
corresponding …B… or lower case letter is used for recessive factor. Here A and B refers to


997) In a gene pool, along with beneficial mutations those mutations also exists which are damaging to an
individual. It has been found that these mutations are irreversible because
I. they have survival value
II. they are acquired
III. they are recessive and carried by heterozygous individuals only
IV. they show genetic drift
Choose the incorrect option for given statement


998) In a medicolegal case of accidental interchange between two babies in a hospital, the baby of the blood
group-A could not be rightly given to a couple with


999) The person famous for experimental genetics


1000) Morgan worked with tiny fruit fly names as


1001) Linkage group is


1002) Some individuals with blood group –A may inherit the genes for blonde hair, while other individuals with
blood group – A may the gene for brown hair. This can be best explained by the principle of


1003) Experimental verification of the chromosomal theory of inheritance was given by


1004) A gene that masks another gane’s expression, is called


1005) Transposons are


1006) Which of the following law was discovered first by Mendel?


1007) Unit of inheritance that required to express a particular trait of organism is called


1008) Sex limited traits are the


1009) Variation stands for differences in traits of progenies from


1010) In which mode of inheritance, do you expect more maternal influence among the offsprings?


1011) Mutagens are


1012) Which is incorrect for Mendelism?


1013) In heterozygous condition, the individual expression of both the alleles in the phenotype is exemplified by


1014) Polyploid derived from two different species is called


1015) Walter Sutton is famous for his contribution to


1016) Humans knew from as early as …A… BC that one of the causes of variation was hidden in …B…
reproduction. They exploided …C… that were naturally present in wild population, A, B and C here refer to


1017) Punnett square was developed by


1018) Female is heteromorphic and male is homomorphic in


1019) The important things to remember are that chromosomes as well as genes occur in …A… . The two alleles
of a gene pair are located on homologous sites on …B… chromosomes
Choose the correct choice for A and B


1020) Who proposed chromosomal theory of linkage?


1021) Which factor expresses itself in homozygous and even in heterozygous condition?


1022) Number of autosomes in human are


1023) A tall plant was grown in nutrient deficient soil and remained dwarf. When it is crossed with dwarf plant
then


1024) A man of blood group-A, marries a woman of blood group-B, both of them are heterozygous for blood
group, chances of their first child having blood group AB will be


1025) Mendel’s laws of inheritance are applicable only for


1026) The factors which expresses only in homozygous condition is


1027) Human skin colour is the example of
I. multiple gene inheritance
II. three separate genes controlling this trait
III. single gene controlling this trait
IV. two gene controlling this trait
V. environment plays a significant role in this trait
Choose the correct option


1028) In haemophilia, a single protein that is a part of cascade of protein involved in …A… of …B… is affected.
Single cut will result in …C… bleeding.
Choose the correct option for A, B and C


1029) In a mutational event, when adenine is replaced by guanine, it is the case of


1030) In cross between yellow round (YYRR) and green wrinkled (yyrr) find out the ratio between seeds having
yellow and green seed colour


1031) Monosomy and trisomy are respectively


1032) I. Haemophilia
II. Cystic fibrosis
III. Sickle-cell anaemia
IV. Colour blindness
V. Cancer
VI. Plague
VII. Phenylketonuria
VIII. Thalassaemia
Choose the correct options for Mendelian disorders


1033) The first hybrid progenies obtained by Mendel were called


1034) What type of gametes will form by genotype RrYy?


1035) A condition, where a certain gene is present in only a single copy in a diploid cell, is called


1036) Frequency of crossing over is …A… in linked gene …B… in unlinked gene.
Choose correct combination for A and B


1037) Which one of the following is necessary to start clotting of blood?


1038) The organism chosen by Mendel to explain the law of inheritance is


1039) A woman is married for the second time. Her first husband was ABO blood type A, and her child by that
marriage was type O. Her new husband is type B and their child is type AB.
What is the women’s ABO genotype and blood type?


1040) A couple has 6 children-5 are girls and 1 is boy. The percentage of having a girl on next time is


1041) On selfing RrTt, we produce 400 plants, find out number of plants with genotype RrTt.


1042) In the ABO system of blood groups, if both antigens are present but no antibody, the blood group of the
individual would be


1043) Barr body in mammals represents


1044) In Barr body (sex-chromatin) of a normal female


1045) In certain plant species, red flower colour is incompletely dominant to white flower colour (the
heterozygote is pink) and tall stems are completely dominant to dwarf stem. If a tall pink plant (TtRr) is
crossed with a tall white plant (TTrr), which one of the following type of plants would be produced in the
offsprings?


1046) Which is true about meiotic cell division?
I. Meosis only occurs in diploid organism without any exception
II. RNA is replicated during S-phase
III. Chromatids of a chromosome separate during anaphase-I
IV. Only sperms are produce by this process


1047) Which of the following pairs of chromosomal mutation are most likely to occur when homologous
chromosomes are under going synapsis?


1048) Down’s syndrome is an example of


1049) Mendel’s works were read out the


1050) Genes of which of the following disorder are present exclusively on the X-chromosome in humans or
concerned with


1051) In a given plant, red colour ( R ) of fruit is dominant over white fruit ( r); and tallness ( T ) is dominant
over dwarfness ( t ). If a plant with genotype RRTt is crossed with a plant of genotype rrtt, what will be the
percentage of tall plants with red fruits in the next generation?


1052) Pick out the correct statements.
I.Haemophilia is a sex-linked recessive disease
II.Down’s syndrome is due to aneuploidy
III.Phenylketonuria is an autosomal dominant gene disorder
IV.Phenylketonuria is an autosomal recessive gene disorder
V.Sickle cell anaemia is an X-linked recessive gene disorder


1053) Sex chromosomes of a female bird are represented by


1054) How many types of gametes may be produced by genotype D/d : E/e : F/f?


1055) If a colourblind women marries a normal visioned man their sones will be


1056) Genic balance theory of sex determination, stated by C B Bridges, is related to


1057) In human beings, 45 chromosomes/single X/XO abnormality causes


1058) When a cluster of genes show linkage behaviour they


1059) Colour blindness is a failure to discriminate between


1060) Linkage group in E .coli is/are


1061) The tendency of offsprings to resemble their parents is called


1062) The major reason for the success of Mendelian experiments was


1063) Which of the following is best suited for codominance?


1064) ABO blood group system is given by


1065) Which of the following is generally used for induced mutagenesis in crop plants?


1066) Genetic recombination is due to


1067) Linkage gene do not shows


1068) Haploids are more suitable for mutation studies than the diploids. This is because


1069) Mendel’s work remain unrecognized for long time due to
I. Communication was not easy
II. Concept of factors which did not blend was not accepted
III. Use of mathematics to explain biological problem was unacceptable
IV. He could not provide any physical proof for the existence of factors
Choose the right combination


1070) Ratio of progeny, when a red coloured heterozygote is crossed with a white coloured plant in which red
colour is dominant to white colour


1071) The possibility of erythroblastosis foetalis occurring during the second pregnancy is when


1072) I. Enborn error of metabolism
II. Homozygous recessive autosomal alleles on chromosomes 12 causes absence of the specific enzyme
III. A specific amino acid do not changes into tyrosine
IV. Accumulation of phenylpyruvic acid and other derivatives leading to mental retardation
The above facts refer to


1073) How many phenotype and genotypes are possible in ABO blood group systems?


1074) Mendel was successful in discovering the principles of inheritance as


1075) The common point of attachment of all the arms of polytene chromosome, is known as


1076) Choose the correct option for allotetraploid


1077) Mutation is more common when it is present in


1078) Allelism refers to


1079) Which one pair of parents is most likely get a child, who would suffer from haemolytic disease of new
born?


1080) Mendel performed test cross to know the


1081) Change in single base pair


1082) Find out the correct statement.


1083) In phenylketonuria, the phenylalanine gets converted to


1084) Which one of the following is a genetically transmitted character?


1085) Multiple phenotype seen in


1086) After a mutation at a genetic locus character of an organism changes due to the change in


1087) In XX and XY type of sex determination, the males are


1088) Dihybrid ratio of test cross 1 : 1 : 1 :1 proves that


1089) Mendel’s findings were rediscovered by


1090) The salivary gland chromosomes in the dipteran larvae are useful in gene mapping because


1091) Percentage of recessive phenotype in a cross between PP and Pp, when P is dominant, p recessive


1092) Genes are made up of


1093) Type of substitution takes place in sickle-cell anaemia is


1094) In the hexaploid wheat, the haploid (n) and basic (x) numbers of chromosomes are


1095) Persons who are colourblind can not distinguish


1096) Haploid-diploid mechanism of sex determination (haplodiploidy) takes place in


1097) Sickle-cell anaemia happens due to …A… mutation in which …B… of haemoglobin is affected.
Fill the correct option for A and B


1098) The gene of sickle cell anaemia is inherited by


1099) A character, which is expressed in a hybrid is called


1100) The first definite proof of mutagenic action of X-rays was given by


1101) If the genotype of an individual consists of only one type of genes at same locus. It is called


1102) The nucleoprotein structures that occur at the ends of the chromosomes are


1103) In polytene chromosomes dark bands are visible. These bands are formed by the position of


1104) Chances of segregation of alleles in gametes are


1105) Hypertrichosis is an example of which inheritance?


1106) The mutagenic agent among following is


1107) The most important example of point mutation is found in a disease called


1108) When tall and dwarf plants are crossed, from which cross 1 : 1 ratio is obtained?


1109) Failure of segregation of chromatid during cell division cycle results in the gain or loss of chromosome
which as called


1110) Genes are present on


1111) Out of 7 contrasting trait pairs selected by Mendel how many traits were dominant and recessive?


1112) Example of environmental determination of sex is/are


1113) Dominant allele are expressed in


1114) If the ratio between X-chromosomes and complete set of autosome is 0.5. Then the individual will be


1115) The leaf colour of certain plants is controlled by one gene. For that gene, the allele G = orange and g =
green. You have a plant with orange leaves, but do not know whether that plant’s genotype is GG or Gg.
If you cross your unknown plant with one of the plants whose genotype is listed below, you will be able to
determine your unknown’s genotype. With which plant would you cross it?


1116) A boy has a normal brother and a colourblind sister. What is true about his parents?


1117) Extranuclear inheritance is a consequence of presence of genes in


1118) Colour blindness is due to defect in


1119) Leaf colour in Mirabilis jalapa is an example of


1120) I. Trisomy of sex (X) chromosome
II. XXY+44
III. 21st trisomy
IV. Sterile male
V. Gynaecomastia
Choose the correct option for Klinefelter’s syndrome


1121) Consider the following statement regarding ABO blood group in human
I. It is controlled by multiple allele
II. It shows codominance
III. Codominance can be manifested phenotypically in human
IV. It follows the Mendel law of inheritance
Which of the following statements (s) are correct?


1122) Brachydactyly is due to


1123) When there are more than two allele controlling the same character. These are called


1124) Monohybrid cross deals with


1125) X-chromosomes of female, in a case of sex-linked inheritance, can be passed on to


1126) The similar and dissimilar sex chromosomes of females and males are described as


1127) Starch synthesis gene in pea plant in heterozygous condition produces starch grain of intermediate size.
This shows


1128) Select the correct bases of DNA, RNA and amino acid of beta chain resulting in sickle cell anaemia.


1129) Statement 1: An organism with lethal mutation may not even develop beyond the zygote stage.
Statement 2: All types of gene mutations are lethal.


1130) Statement 1: Phenylketonuria is a recessive hereditary disease caused by body’s failure to oxidise an
amino acid phenylalanine to tyrosine, because of defective enzyme.
Statement 2: It results in the presence of phenylalanine acid in urine.


1131) Statement 1: Polytene chromosomes have a high amount of DNA.
Statement 2: Polytene chromosomes are formed by repeated replication of chromosomal DNA without
separation of chromatids.


1132) Statement 1: In humans, the gamete contributed by the male determines whether the child produced
will be male or female.
Statement 2: Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on
X-chromosome and some on Y-chromosomes.


1133) Statement 1: Persons suffering from haemophilia fail to produce blood clotting factor-VIII.
Statement 2: Prothrombin producing platelets in such persons are found in very low concentration.