Practice Test


1) Co-repressor is a:


2) Reverse transcription was discovered by:


3) In the Operon concept, the regulator gene regulates chemical reactions in the cell by:


4) Central dogma of cytogenetics is:


5) In an E. coli according to Operon concept, an operator gene combines with:


6) Exons and introns are parts of:


7) Eukaryotes have:


8) In Rous sarcoma virus:


9) Presence of F factor in bacteria:


10) The viral genes express by:


11) Which of the following is not carcinogen?


12) According to Operon concept, regulator gene form:


13) Which virus has a double stranded RNA?


14) In lysogenic cycle, the virus is:


15) In bacteria, exchange of genetic material between two different cells is brought by the process of:


16) Phage host represents:


17) Regulated unit of genetic material is called:


18) A retrovirus is:


19) Bacteriophages are:


20) Provirus differs from prophage with regard to:


21) Which virus has a rod shaped structure?


22) Tryptophan Operon is:


23) Oncogenic viruses are harmful in:


24) Which of the following viruses have been extensively used to fuse cells in tissue culture:


25) Jumping genes is maize were discovered by:


26) Thalessemia is an example of:


27) Who found occurrence of sexuality in bacteria?


28) Operon consists of following:


29) Restriction enzymes are used in genetic engineering because:


30) Wild type E.coli cells are growing in a normal medium with glucose. They are transferred to medium containing only lactose as the sugar. Which one of the following changes take place?


31) An environmental agent that triggers transcription from an operon is a:


32) The lac operon is an example of:


33) In split genes, the coding sequences are called:


34) In case of cyanobacteria:


35) The sequence of structural genes of Lac operon is:


36) Which virus has a single stranded DNA:


37) In lytic cycle, the virus is:


38) Resistance to antibiotics is a genetic trait that spreads naturally from one type of bacterium to:


39) Reverse transcriptase is:


40) Transduction in bacteria is mediated by:


41) The nuclease enzymes which begins its attack from a free end of a polynucleotide:


42) Normally, DNA molecule has A-T, G-C pairing. However these bases can exist in alternative, valency consistent status, owing to rearrangement called:


43) When DNA is exchanged between two bacteria via cytoplasmic bridges, the process is called:


44) When a bacteriophage, in its lytic phase carries some of the bacterium partially digested chromosome with it to another host cell, the process is called:


45) In general, bacterial genes are regulated at the time of:


46) The activity of a repressor depends on whether:


47) In gene therapy, DNA is inserted in a cell to compensate for:


48) A gene carried by recombinant DNA is cloned when:


49) A piece of nucleic acid used to find a gene, by forming a hybrid with it, is called as:


50) Which of these viruses has DNA that occurs in both linear form and circular form?


51) Palindromic sequence are recognized by enzymes:


52) Which of the following is a palindromic sequence of nucleotides?


53) Which is not an oncogenic virus?


54) Restriction enzymes are nucleases and:


55) Which is must for genetic engineering?


56) Restriction endonuclease enzymes (RE) also called microscissors are widely used in genetic engineering. They cleave up foreign DNA at specific sites. These enzymes are synthesized by:


57) Restriction endonuclease are enzymes discovered by Arber and Mathani (1962) and obtained from bacteria only. They are used as microscissors in genetic engineering. They recognise specific sequence of bases at a particular site, usually 4-6 base pairs and:


58) Sticky ends of DNA strand are:


59) Eli Lilly and Co. is famous for:


60) Chimera DNA is:


61) Callus and cancer both are undifferentiated mass of cells formed by uncontrolled mitosis. They differ as:


62) The experiments of Briggs and Kings clearly proved that:


63) One important consequence of interference of gene expression by another gene may be:


64) In the Tryptophan operon, Tryptophan acts as:


65) Enzymes required at the time e.g., for respiration are called:


66) Two scientists working in Pasteur Institute proposed a gene action model and got Nobel Prize in 1965. Names:


67) Recent work in genetics being carried out in U.S.A. and Japan is on:


68) Consider the situtation : Synthesis of protein is going on, an amino acid is added in the medium, synthesis is stopped, what is involved?


69) The gene which increases the frequency of mutation in other genes is called:


70) Term metaxenia denotes the effect of pollen on:


71) There is no masking in expression of genes in Neurospora, because it:


72) Human growth hormone is now produced in large quantities by recombinant DNA technology. The previous source of this hormone, for treating pituitary dwarf, was:


73) How does gene expression occur in prokaryotes?


74) The minimum length of cistron in base pairs which synthesizes a polypeptide of 50 amino acids is:


75) In a codon wobbling is restricted to:


76) A community of similar individuals living a circumscribed area at a given time and capable of interbreeding is called:


77) House keeping/constituent genes are:


78) A split gene is:


79) Gene expression in eukaryotes at a time never exceeds:


80) Retroviruses are implicated as a cause for cancer in humans because they:


81) When lactose is present:


82) Introns occurs in:


83) Aflatoxin produces cancer of the liver by inducing:


84) The number of nucleotide present in yeast alanyl-t-RNA are:


85) Britten and Davidsons (1969) gene-battery model is:


86) Nirenberg synthesized a mRNA containing 34 polyadenine (A-A-A-A-A-A) and found a polypeptide formed of 11 polylysine, this proved that genetic code for lysine was:


87) The DNA sequence of Lac-gene shows a mutation where the middle base of a triplet code has been substituted. However, the gene does not show any mutation and expression normal. This may be due to:


88) Redundant parts of DNA or a gene are called:


89) According to 1991 figures, about how many human genes have been mapped?


90) Eugenics, Euthenics and Euphenics are related with Human Genetics. Which is concerned with improvement of present human race by providing better living condition i.e., good nature and nurture?


91) Lac, operon of E. coli contains in continuity:


92) Bacterial resistance to antibiotic is a genetic trait carried in the bacterial:


93) In a tryptophan operon model, formation of tryptophan is restricted by:


94) How many types of the genes the Lac operon model includes:


95) In a lac-operon model, the addition of lactose induces the synthesis of:


96) A collection of clones (genetically similar cells/organisms) having recombinant DNA is called:


97) Hybrids are often superior to either parents due to:


98) Controversies about doubtful parentage can now be settled by employing:


99) Dr. Hargobind Khorana has been awarded Nobels prize for research on:


100) Barbara McClintock's work showed that in maize:


101) Two strains of bacterial suspensions are separated from one another with the help of bacteria proof glass filters, which of the following process would not occur?


102) Each codon present on m-RNA and anticodon present in t-RNA is composed of:


103) Which of the following unit is unrelated to DNA or gene?


104) Recently the application of genetics in biotechnology and industry has become topic of discussion among different countires. This will become the part of:


105) Galton is regarded as Father of Eugenics (science of being well born). Eugenic is concerned with:


106) Dysgenic eugenics is to:


107) The basis for DNA finger printing is:


108) The Nobel prize of physiology and medicine in 1989 was awarded to:


109) The recent techinque used for separating fragments of DNA is:


110) Genes that are involved in turning on or off the transcription on a set of genes are called:


111) Why is recombinant DNA technology called genetic engineering?


112) Another popular name of recombinant technology is:


113) Enzyme which acts like a scissor in genetic engineering is:


114) A vector is used to carry foreign DNA in genetic engineering. Which one of the following is used as vector?


115) The most novel vector having 2 sites for RE enzymes are:


116) Restriction enzymes have been found in:


117) Which one of the following pairs is correctly matched?


118) A restriction enzymes breaks bonds between the:


119) The sub branch of genetic engineering through which disorders are treated is called Gene Therapy. The father of biochemical disorder is:


120) Concentration of inducible enzymes in the presence of their substrate may be increase:


121) A poly-uridylic (Poly-U) chain of mRNA is called:


122) The Eco-RI enzymes is obtained from:


123) The DNA whose genes are to be transferred is multiplied through bacterial DNA (vectro or vehicle or carrier to DNA) in genetic engineering. This DNA is called:


124) Cryptogram is:


125) Ability to absorb foreign DNA is:


126) The first artificial plant hybrid was made around 1717 by?


127) Gene which is responsible for synthesis of polypeptide chain is called:


128) An envelope surrounds the virus in:


129) During lytic cycle, viral DNA is not affected by nucleases produced by it as:


130) Restriction endonucleases ECO RI cleaves palindrome site of DNA duplex at:


131) Which of the following organelles is associated with genetic engineering?


132) Plants that receive the foreign genes through genetic engineering are called:


133) A cell coded protein that is formed in response to infection with most animal viruses is called:


134) Which of the following pairs is correctly matched?


135) Viruses like herpes virus, Epstein-Barr virus, AIDS, HIV resemble each in being:


136) AIDS is characterised by:


137) Reverse transcription was frist shown by:


138) Teminism was discovered in:


139) First human interferon (antiviral protein) was produced by:


140) First man made (genetically engineered) industrially important organism was Pseudomonas fluorecens called Super Bug. It was made by:


141) Viral genome is changed to prorvirus/prophage state by:


142) That nuclei control cell differentiation was proved in frog and toad by:


143) A sequential expression of a set of human genes occurs, when a steroid molecule binds to the:


144) During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle like structure. What is it's DNA binding sequence?


145) What would happen if in a gene encoding a polypeptide of 50 amino acids will be (UAC) is mutated of UAA?


146) How do the proto-oncogenes changed to oncogenes?


147) How does a totipotent cell undergo differentiation?


148) Which is the initial step in m-RNA maturation process?


149) The central dogma of protein synthesis in teminism is:


150) Molecular basis of organ differentiation depends on the modulation in transcription by:


151) Which of the following correctly defines a transgenic animal:


152) There are special proteins that help to open up DNA double helix infront of the replication fork. These proteins are:


153) Who got the Nobel prize in medicine for their discovery of 'G-proteins' and the role of these proteins in the cells:


154) Exonucleases cleaving nucleotides one at a time from the end of the polynucleotide chain are:


155) Complete transduction is:


156) Genetic engineering is possible because:


157) Two bacteria found to be very useful in genetic engineering experiments are:


158) At the time of organogenesis genes regulate the process at different levels and a different time due to:


159) In Negative operon:


160) Restriction enzymes:


161) Process of introduction of foreign gene far improving genotype is called:


162) Which one of the following makes use of RNA as a template to synthesize DNA?


163) Which one of the following conditions though harmful in itself, is also a potential saviour from all mosquito borne infectious disease?


164) In E. coli, during lactose metabolism repressor binds to:


165) The genes are responsible for the growth and differentiation in living organisms through the regulation of:


166) Which of the following is specifically used in genetic engineering?


167) Restriction endonucleases:


168) Cancer cells are more easily damaged by radiation than normal cells because they are:


169) DNA finger printing refers to:


170) What kind of evidence suggested that man is more closely related with chimpanzee than with other hominoid apes?


171) In transgenics, expression of transgene in target tissue is determined by:


172) The Ti plasmid, is often used for making transgenic plants. This plasmid is found in:


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


174) Supercoiled DNA can be traced in:


175) Phosphorus is present in:


176) In a given DNA segment ATG, ACC, AGG, ACC, CCA, ACA, the first base gets mutated. The effects of this on coding by this DNA segment will result in:


177) Okazaki fragments are joined in a correct sequence by:


178) In the lac operon, the structural genes are switched off when:


179) In lac operon structural gene 'z' is responsible for the synthesis of the enzyme:


180) When lactose is added to the culture of E. coli, a few of its molecules get into the cells with the help of:


181) During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called?


182) In the lac operon model, lactose molecules function a is:


183) Protein synthesis in an animal cell occurs:


184) E. coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because:


185) Differentiation of organs and tissues in a developing organism, is associated with:


186) Intron transcripts in heterogenous nuclear RNA (hn-RNA) are removed and exon transcripts are joined together under the direction of protein complexes. These complexes are:


187) In regulation of gene expression in prokarytoes:
(a) Lactose acts as the suppressor for gene expression
(b) Tryptophan acts as the inducer for gene expression
(c) Regulator gene is the one that produces the repressor molecule


188) Tumour causing viruses carry which of the proto-oncogene?


189) Which of the following acts as genetic material in retro viruses?


190) The term genome is used for:


191) Synonymous codons are:


192) Select correct one:


193) Regulation of gene activity is carried out by:


194) In Tryptophan operon, a repressor consists of co-repressor and apo-repressor. These two consist of:


195) In lac operon model, the correct sequence of genes is:


196) Prophage is formed by integration of E. coli DNA with:


197) The phenomenon by which the phage DNA exists as part of the host DNA is called:


198) The collection of cloned DNA segments obtained from complete genome is called:


199) In operon model, regulator gene functions as:


200) Genes involved in turning on and off of structural genes are:


201) Lac operon is related to:


202) According to the operon concept, the regulator gene regulates chemical reactions in the cell by:


203) The modern concept of gene is that it is:


204) SV 40 has five genes but the type of proteins synthesised by it is more than twice the number of genes present in it. It shows the presence of:


205) Identify the true statements -
I. Pullorum disease of poultry is caused by virus.
II. Drones are produced by parthenogenesis.
III. Heterosis or hybrid vigour is the phenotypic superiority of the hybrid over either of its parents in one or more traits.
IV. A clone contains and expresses genetically engineered gene known as transgene.
V. Cross breeding is practised to develop homozygous pureline.