Practice Test


1) Term ecosystem was coined by:


2) Biotic component of an ecosystem include:


3) Which is the most stable ecosystem?


4) In a biotic community, primary consumers are:


5) If we completely remove the decomposers from an ecosystem, the ecosystem functioning will be adversely affected because:


6) Food chain will end with:


7) Which of the following is one way flow rather than a two way or cyclic flow?


8) The importance of ecosystem lies in:


9) The driving force for an ecosystem is:


10) About how much of solar energy that falls on the leaves of a plant is converted to chemical energy by photosynthesis?


11) Energy and nutrient enter a community by way of:


12) A consumer whose carbon atoms have already passed through three species is a:


13) Average annual precipitation in a desert biome is:


14) A sequence of speices through which the organic molecules in a community pass is called:


15) Savannahs are:


16) Most food chains are composed of:


17) A micro-climate is controlled mostly by factors associated with:


18) In which of the following habitats does the diurnal temperature of soil surface vary most?


19) A biome with high temperature, high rainfall no seasonal change and soil rich in mineral and humus is:


20) A plant eaten by herbivorous animals which in turn is eaten by a carnivorous animal, it forms a:


21) A pond is a:


22) Which of the following communities would have trees?


23) Which of the following has a vegetation structure with only one level?


24) What type of pyramids are commonly referred to in the ecological studies?


25) Which type of system does the earth along with its atmosphere constitute?


26) Enrichment of habitat (say pond) with nutrients is called:


27) Wolves and lion may be said to occupy the same trophic level because:


28) About how much of the chemical energy within the producers tissue become chemical energy within herbivore tissue:


29) The most diverse oceanic communities are in the:


30) Which of the following aquatic ecosystem has very little primary productivity?


31) Which of the following statement is true about ecological relationship?


32) Light compensation zone refers to the zone:


33) Aquatic ecosystem covers how much of the earth's surface?


34) What are biotic components?


35) The flora and fauna in lakes and ponds are:


36) The source of energy in an ecosystem is:


37) The energy storage at consumer level is called:


38) Most hard competition for food, light and space is seen in:


39) The leaves of Lotus bear stomata:


40) The typical biome of an area having 20-40 inches of rainfall is:


41) An ecosystem resists change because it is in a state of:


42) Ecosystem has two components:


43) The number of producers within a specified area would be maximum in:


44) In an ecosystem, a big fish eats small fishes which eat water fleas supported by phytoplanktons. The water fleas in this ecosystem are:


45) Which one of the following represents the largest population in an ecosystem?


46) With regard to ecological food chain, man is a:


47) The first link in a food chain is always a green plant because:


48) A food chain is represented by:


49) Organisms linked in a food chain represent:


50) Free floating organisms are termed:


51) The bottom-dwelling organisms are:


52) First trophic level is represented by:


53) In a grassland top consumers are:


54) The food chain in which micro-organisms absorb and breakdown the energy rich compounds synthesized by the producers is:


55) Lichens do not normally grow in cities:


56) Primary productivity of ecosystem refers to:


57) The individuals in the uppermost ring of pyramid represent the one with:


58) The pyramid of number of individuals per unit area in a grassland ecosystem will be:


59) Ecological niche is:


60) Which of the following food chains is correct?


61) 'Greenhouse effect' is:


62) For recycling of materials which one is necessary?


63) Energy flow in an ecosystem is:


64) The pyramid of energy in a terrestrial ecosystem may be:


65) Green plants are:


66) Solar energy can be trapped to the maximum capacity by:


67) The equilibrium of species is disturbed by:


68) A food chain starts with:


69) Biological equilibrium is an equilibrium among the:


70) When the number of organisms at successive levels are plotted, they assume the shape of a pyramid. This is called:


71) The salt concentration in open sea is about:


72) The upper vertical zone upto the depth of 200 metres is known as:


73) In a food chain, the largest number is of:


74) Ecosystem is a self-sustanining unit because it consists of:


75) A component of physical environment of an ecosystem is:


76) In a food chain animals constitute the:


77) Second order consumers are:


78) Active swimmers are:


79) Food web is constituted by:


80) Vegetation found around the Mediterranean coast is called:


81) An ecosystem is a complex interacting system of:


82) Which of the following is truly a biome?


83) The ecological niche of an organism is its:


84) Which of the following forest is more diverse?


85) The solar energy is trapped to the maximum by:


86) Agroecosystem is a:


87) Mangrove vegetation is found in:


88) In grassland ecosystem the pyramid of energy is:


89) Photic zone is spread upto a depth of:


90) Chaparral occurs in Mediterranean area and rainfall occurs during?


91) Daily tidal cycle recurs after:


92) Pyramid of number is based on:


93) Each couple should produce only two children which will help in:


94) The trophic level of lion in a forest ecosystem is:


95) About how much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?


96) About how much of net primary productivity of an aquatic ecosystem is eaten and digested by herbivores?


97) Life without air is:


98) Trophical dense forest is due to:


99) Pyramid of energy is always:


100) A kite eats mouse, mice live on grains. Hence the kite is a:


101) The composition of soil air if affected by:


102) Plants growing in alpine zone are short due to:


103) Plants growing near the sea shore are generally resistant to:


104) An anatomical feature is which exclusively develops to counter high velocity of wind:


105) The classification of plant groups on the basis of temperature differentiating four zone such as megatherms was proposed by:


106) Flowering is induced if germinating seeds are exposed to:


107) The percentage of light from total solar input utilized by plants:


108) Albedo value refers to:


109) According to Geiger, the percentage of light reflected by the clouds is:


110) The albedo value of a forest is around:


111) The aquatic thermal strata where no temperature gradients are observed is called as:


112) The alpine forests are classed under the plant group called:


113) The optimum temperature for seedling growth in the upper Gangetic plains is around:


114) When a plant of hot climate is transferred to colder regions, it gets an injury called:


115) In western Himalayas, the Betula trees usually occur in:


116) Annual carbon fixation by photosynthesis is:


117) Annual world precipitation is:


118) Maximum oxygen comes from:


119) The main nitrogen reservoir in the biosphere is:


120) The largest reservoir of sulphur in the biospere is the:


121) The largest reservoir of phosphorus in the biosphere is the:


122) Which one of the following pairs is a sedimentary type of biogeochemical cycle?


123) Dense evergreen vegetation of broad sclerophyllous leaves and shrubs with fire resistant resinous plants is known as:


124) Correct sequence in ascending order:


125) Which of the following factor is responsible for animals to be successful:


126) Perfect example of interdependence of plants and animals upon each other is:


127) In any ecosystem or biological system there is transfer of energy at different trophic levels. The study of energy transfer at different trophic level is known as:


128) Keystone species in ecosystem are those:


129) Which of the following ecosystem has highest rate of gross primary production:


130) The tendency of an organism to maintain internal equilibrium in response to any change in its environment is called or a tendency of biological systems to resist change so as to remain in a state of equilibrium is called:


131) 10% energy transfer law in food chain was first given by:


132) In India Tropical rain forests occur in:


133) Pedology is the study of:


134) When an organism is benefited without affecting the other is called:


135) From first or lower trophic level to upper trophic level energy is degraded from high grade form to low grade form, it can be made clear from:


136) In an ecosystem bacteria are considered as:


137) A lake ecosystem is:


138) The ecological pyramids are of:


139) In which ecosystem species diversity is low:


140) The succession as a result of changes in communities on earth's surface is called as:


141) The climatic and edaphic factors working on a community is collectively known as:


142) Individuals (organisms) of the same species inhabiting in a particualr locality constitute:


143) During adverse season therophytes survive by:


144) Plants that lack perennating buds and are annuals are placed in the life form:


145) The concept of life form classes and biological spectrum was proposed by:


146) The population of a place or an area tends to increase when:


147) Eichhornia crassipes is a:


148) Which one of the following is a correct food chain:


149) Niche of a speices in an ecosystem refers to its:


150) In a food chain of the largest population is that of:


151) If forest cover is reduced to half, what is most likely to happen on a long term basis:


152) The nature of climax community will depend upon:


153) Extremities, tail and ear are relatively shorter in animals living in cold regions as compared to those inhabiting warmer zones. This is:


154) Food levels in an ecosystem are called:


155) First link in any food chain is green plant:


156) Actively moving or swimming animals in aquatic systems are:


157) Proper food chain is:


158) The species losses in tropical countries is mainly due to:


159) Which of the following can be considered an ecosystem?


160) A large number of organic compounds can be decomposed by:


161) Which is the main causative factor of desertification:


162) The abundance of a species population within its habitat is called:


163) Pyramid of numbers illustrates:


164) In an ecosystem, there is a flow of energy from the producers to the consumers at different levels. This is known as the:


165) Eutrophication in water results in:


166) In a forest ecosystem, the fungi come under the category of:


167) Identify the incorrect statement among the following statements on the effect of deforestation:


168) The dominant second trophic level in a lake ecosystem is:


169) Which of the following is the most characteristic feature of a xeric environment:


170) Deciduous forests are characterised by:


171) We refer to the following as the food chain:


172) In an ecosystem there is flow of energy at different trophic levels. This is as follows:


173) In a tiger reserve the tiger is placed in the:


174) The term ecosystem was coined by:


175) A rat feeding on potato tuber is:


176) Lentic ecosystem occurs in which kind of water?


177) Biome had organisms of various trophic level?


178) Secondary proudcers are:


179) Drought resistance of succulents is connected with:


180) Ecosystem of a pond is:


181) Mangrove of marshy Sundarbans is characterised by:


182) Correct sequence in a food chain is:


183) Peacock eats a snake and snake eats frog and frog eats insect while insect eats green plant, then position of peacock is:


184) Organisms living at the bottom of a lake are:


185) No animal can live:


186) Hibernation occuring in certain animals is:


187) In an ecosystem, trophic level of man is:


188) Tip of an ecological pyramid is occupied by:


189) Zooplanktonic forms are:


190) Which of the following occurs in abiotic component of ecosystem?


191) A treeless biome is:


192) A man-made microecosystem is:


193) Which one has always a steeper vertical gradient?


194) Which one is exclusive xerophytic adaptation?


195) Which one has evergreen vegetation and drought adapted animals?


196) Which part of the world has high density of organisms?


197) Viviparity and pneumatophores are features of:


198) Trophic levels are formed by:


199) An ecosystem has which of the following two components?


200) The atmospheric humidity is measured by:


201) The concept of ecological pyramids was developed by:


202) From feeding on herbivorous insect is:


203) Maximum biomass of autotrophs in oceans is made of:


204) Terai forest is:


205) Savannah is found commonly in:


206) A recently discovered ecosystem is:


207) Controlling factor in ecosystem is:


208) Transition zone between two vegetational types is:


209) Plant decomposers are:


210) The ecosystem consists of:


211) Desert can be converted into green land by planting:


212) In food chain, lion is a:


213) Which ecosystem shows maximum genetic diversity?


214) Which of the following is correctly matched?


215) Organisms found at the bottom of sea are:


216) X is eating curd/yoghurt. For this food intake in a food chain he should be considered as occupying:


217) These belong to the category of primary consumers:


218) If the high altitude birds become rare or extinct, the plants which may disappear along with them are:


219) An ecosystem which can be easily damaged but can recover after some time if damaging effect stops will be having:


220) If by radiation all nitrogenase enzymes are inactivated, then there will be no:


221) The Great Barrier Reef along the east coast of Australia can be catergorized as:


222) Which one of the following pairs is mismatched?


223) Which one of the following is correct matching of plant, its habit, and the forest type where it normally occurs?


224) Energy transferred from one trophic level to another is:


225) Maximum absorption of rainfall water is done by:


226) The pyramid of energy is always upright for any ecosystem. This situation indicates the fact that:


227) Which of the following is called as a detritivore?


228) Which one of the following is not used for construction of ecological pyramids?


229) Increased asthmatic attacks in certain seasons are related to:


230) Which one of the following ecosystem types has the highest annual net primary productivity?


231) Consider the following statements concerning food chains:


232) Large Woody Vines are more commonly found in:


233) Which one of the following statements for pyramid of energy is incorrect, whereas the remainig three are correct?


234) Mass of living matter at a trophic level in an area at any time is called:


235) Of the total incident solar radiation the proportion of PAR is:


236) In an aquatic ecosystem, which of the following are dominant in shallow water?


237) Which of the following processes is involved in decomposition of detritus?


238) What is the mean net primary productivity of tropical rain forest ecosystem?


239) One of the following fall in the category of lowest productivity category?


240) What is the key function of ecosystem?


241) Photosynthetic efficiency is represented by:


242) Which of the following is/are involved in the ammonification during nitrogen cycle?


243) Mean annual rainfall (mm) in the tropical rain forest is:


244) The primary productivity in grassland is directly related to:


245) Which of the following is/are common trees and shrubs in savannah:


246) Select the correct statement:


247) Which of the following is an abiotic component of an ecosystem?


248) Which of the following processes helps in nutrient conservation?


249) Which of the following represents the sedimentary type of nutrient cycle?


250) Which of the following is free living nitrogen fixing bacteria present in soil?


251) What fraction of assimilated energy is used in respiration by the herbivore?


252) Select the correct statement:


253) Which of the following organisms and trophic levels is mismatched?


254) Chemosynthetic bacteria found around deep-sea vents are examples of


255) In an ecosystem,


256) Primary productivity


257) The open ocean and tropical rain forest are the two largest contributors to Earth's net primary productivity because


258) Productivity in terrestrial ecosystems is affected by


259) Secondary productivity


260) Which of the following is not true of a pyramid of productivity?


261) Biogeochemical cycles are global for elements


262) Which of these processes is incorrectly paired with its description?


263) Carbon cycles relatively rapidly except when it is


264) What do primary producers have available to convert into biomass?


265) Which of the following trophic levels would have the largest numbers of individuals?


266) Which of the following elements is not a major component of living systems?


267) Most of Earth's nitrogen is in


268) The gas that is removed from the atmosphere by plants and algae is


269) Most of the world's carbon is found


270) Photosynthesis and respiration are central to which cycle?


271) In the past 150 years there has been a major new input to the carbon cycle. What is it?


272) Nitrogen is often in short supply in terrestrial ecosystems. Why?


273) The phosphorus cycle differs from the carbon cycle in that


274) Which of the following statements regarding the movement of energy and nutrients through ecosystem is true?


275) Which of the following changes would not result in an increase in net primary production?


276) On average, how much of the energy assimilated at one trophic level is converted to production the next trophic level (excluding the conversion of sun-light into chemical energy by plants)


277) Which of the following always has a "pyramidal" shape, that is decreasing values at higher trophic levels?


278) Which of the following statements regarding the hydrological cycle is false?


279) In biogeochemical cycles, elements that cycle fastest


280) Which of the following biogeochemical cycles is characterized by a major reservoir that is gaseous, and a major inorganic form that can only be utilized by a small group of bacteria and cyanobacteria?


281) Which of the following biogeochemical cycles is characterized by a form which is a major greenhouse gas?


282) Which of the following biogeochemical cycles lacks a gaseous phase?


283) Which of the following biogeochemical cycles has a gaseous phase released by volcanoes and fumaroles?


284) Which of the following biogeochemical cycles has a major reservoir in sedimentary rock?


285) In the human-induced condition called eutrophication, the main biogeochemical cycle that is altered is the ______ cycle, and the effect is to create ______ conditions and decrease species diversity.


286) Slow rate of decomposition of fallen logs in nature is due to


287) In the human-induced condition called acid precipitation, the main biogeochemical cycles that are altered are the ______ cycles, and one effect in lakes is the _______ of populations of nitrifying bacteria.


288) Which of the following is not a part of either gross or net primary production in plants?


289) Which of the following statements about food chains and energy flow through ecosystems is false?


290) Assuming that the energy transfer efficiency between trophic levels is 10%, how much grain would be required to produce 70 kg of human biomass if the grain is eaten by cows and the cows are eaten by humans?


291) Grasslands can support greater grazing rates by herbivores than forests because


292) An inverted pyramid of ______ may occasionally be observed in _______ communities.


293) Which of the following is not an objective of integrated pest management?


294) Which of the following could not be considered an ecosystem?


295) In which of the following compartments of the global ecosystem would circulation of materials be affected by Earth's revolution around the sun?


296) Which of the following statements about biogeochemical cycles is not true?


297) Which of the following is true about the amount of sunlight and heat arriving on Earth?


298) The total amount of energy that plants assimilate by photosynthesis is called


299) The amount of energy reaching an upper trophic level is determined by


300) Select the correct combination of statements (I - IV) regarding the characteristics of productivity.
I. The rate of biomass production is called productivity and is expressed in terms of a kcal m^(-2).
II. Gross primary productivity is rate of production of biomass during photosynthesis.
III. Gross primary productivity minus respiration loss is called net primary productivity.
IV. Primary productivity depends only on the plant species inhabiting a particular area. The correct statements are


301) Fill in the blanks, in the following simplified model of a nutrient cycle.


302) The given figure best represents


303) The pyramid of energy is always upright for any ecosystem. This situation indicates the fact that


304) Valuable, practical services that help to preserve ecosystems performed by nature are called _____.


305) Identify the incorrect statement from the following


306) The correct definition of ecosystem is


307) When a peacock eats snakes which eats insects thriving on green plants, the peacock is


308) In an ecosystem, the population of


309) Which is correct sequence in the food chain?


310) When a big fish eats a small fish which eats water fleas supported by phytoplankton, the water fleas are


311) Graphical representation of biomass relationship between the producer and the consumers is called


312) A food chain consists of


313) In a forest ecosystem, green plants are


314) In a food chain, herbivores are


315) Percentage of nitrogen in air is about


316) The transfer of energy in food chain is


317) A vegetarian food habits of man help in getting


318) The gaseous portion of outer earth surface is


319) Which of the food chain will be advantageous in terms of energy?


320) Ecological niche refers to


321) Which of the following biome has largest number of species?


322) Chapparal occurs in area


323) Name the sedimentary cycle that has a small gaseous components


324) The secondary productivity means


325) Which one of the following has the largest population in a food chain?


326) Second most important trophic level is a lake is


327) Secondary producers are


328) What is the percentage of photosynthetically active radiation (PAR), if incident solar radiation is considered 100%.


329) Identify the incorrect statement from the following.


330) Which of the following process will be most adversely affected if microorganisms are removed from a forest ecosystem?


331) Food chains differ from food webs in that -
A. food chains are a single sequence of who eats whom in a community.
B. food chains better represent the entire community.
C. food webs represent the complex interaction among food chain.
D. food chain is the flow of energy in a population.


332) Which of the following factors influence communities -
A. Climate
B. Species interaction
C. Feeding relationships among organisms
D. Succession


333) Which of following is/are trend (s) in ecological succession -
A. an increase in complexity of species
B. an increase in productivity
C. an increase in community stability and species diversity
D. a decrease in non-living organic materials.


334) Primary productivity depends upon -
A. The plant species inhabiting a particular area.
B. Availability of nutrients.
C. Photosynthetic capacity of plants.


335) Which of the following ecological pyramids may be upright or inverted?
A. pyramid of energy
B. pyramid of number
C. pyramid of biomass
D. none.


336) Grasslands can support greater grazing rates by herbivores than forests because


337) The total amount of energy that plants assimilate by photosynthesis is called


338) Which of the following statement(s) is/are correct about biogeochemical cycle -
A. Carbon and nitrogen cycle faster than phosphorus cycle.
B. All biogeochemical cycles include both organisms and non-living components.
C. Most elements remain longest in the living portion of their cycle.
D. The chemical elements used by organisms in large quantities cycle back and forth between organisms and environment.


339) The cycle most important for modifying temperature fluctuation is


340) Which is/are true regarding ecosystem?
A. Self sufficient unit.
B. Cyclic exchange of materials between living beings and environment.
C. Only requirement is input of energy.
D. Characterized by a major vegetation type.


341) Which of the following are artificial aquatic ecosystems?
A. large dams and reservoirs
B. lakes and canals
C. fishery tanks and aquaria
D. river


342) The phosphates remain outside the natural cycle for a long time


343) The term used to describe all the species and physical factor at a site is the


344) The amount of energy that is left to build bodies is termed


345) A. P-cycling depends only on biological processes.
B. In general, food chains are more stable then food webs.
C. The food chain that depends on decomposing plant or animal matter is the detritus.
D. Humans can feed at several trophic levels and are classified as omnivores.


346) Combustion of fossil fuels most directly affects the


347) Which of the following include(s) ecosystem services -
A. Purification of air and water by forests.
B. Forests mitigate droughts and flood.
C. Forests act as store house of carbon.
D. Forests influence hydrological cycle.


348) Select the correct statement(s) -
A. The factors affecting decomposition are chemical nature of detritus and the climatic factors.
B. It detritus is rich in lignin and chitin decomposition is very fast.
C. Decomposition is very slow if the detritus is rich in nitrogen.
D. Detritus is the raw material for decomposition.


349) A. The amount of living matter (biomass) present at every trophic level is called standing crop.
B. Saprophytes are not given any in ecological pyramids.
C. Ecological pyramid does not account the same species belonging to two or more trophic levels.
D. Humus is reservoir of nutrients.


350) Which of the following is/are incorrect -
A. All ecosystems are constant in size.
B. In nature food chains exist, not food web.
C. Flow of energy in ecosystem is linear.
D. Gene flow occurs between 2 different population (of 2 species)


351) Ecological efficiency at each trophic level of a particular ecosystem is 20%. If green plants of the ecosystem capture 100 units of energy, about how many units of energy will be available to support herbivores


352) Ecological succession is


353) Succession is a


354) A dynamic equilibrium is established between community and environment when


355) Which is correct?


356) Herbivores are


357) Food chain consists of


358) Autotrophs are


359) In which of the following areas does the primary succession occur?


360) Which of the following statements about the food chain is false?


361) Go through the following statements.
A. Primary productivity of all ecosystem is a constant.
B. The annual net primary productivity of the whole of the biosphere is 17 million tons (dry weight) of organic matter.
C. Net primary productivity is the amount of biomass available for consumption by carnivores.
D. Secondary productivity is defined as the rate of formation of new organic matter by decomposers.
E. Primary productivity depends on the plant species inhabiting a particular area.
Which of the above the statements about productivity is true ?


362) Arrange the following ecosystems in increasing order of mean NPP (Tonnes/ha/year)
A. Tropical deciduous forest
B. Temperate coniferous forest
C. Tropical rain forest
D. Temperate deciduous forest


363) The energy invested in the production of new tissue by autotrophic organisms is termed


364) Which of the following is true of net primary production?


365) Which of the following statements is incorrect?


366) Which of the following is NOT a reason why productivity declines from one trophic level to the next?


367) Which of the following is NOT true of a food web?


368) Which of the following is NOT a hypothesis for why food-chain length is limited?


369) Which of the following is NOT a basic aspect of biogeochemical cycling?


370) Several of the major human impacts are farming, logging, burning and soil erosion. They all result in accelerated nutrient loss by what common mechanism?


371) In a comparative study of grassland ecosystem and pond ecosystem it may be observed that


372) Why are changes in the global carbon cycle important?


373) Go through the statements.
A. In terrestrial ecosystem, maximum energy is present in T1.
B. In grassland ecosystem, the pyramid of biomass is upright.
C. In pyramid of food, the producers occupy the base.
D. Energy flow in an ecosystem is bidirectional.
E. If all green plants of earth are destroyed, all animals shall die ultimately.
F. The typical biome of an area having 50 to 100 cm of rainfall is grassland.
How many of the above statement(s) is wrong?


374) The annual net primary productivity of the whole biosphere is approximately.


375) The important step in the process of decomposition in order is


376) In trophic level of our ecosystem we belong to


377) Which of the following is false?
I. Quantity of biomass in a trophic level at a particular period is called standing crop.
II. The energy content in a trophic level is determined by considering a few individuals of a species in that trophical level.
III. The succession that occurs in nearly cooled lava is called primary succession.
IV. Rate of succession is faster in the secondary succession.
V. Phytoplanktons are the pioneers in aquatic succession.


378) The component of the ecosystem are seen to function as a unit when you consider which of the following aspects -
A. Productivity
B. Decomposition
C. Energy flow
D. Nutrient cycle


379) Which of the following is correct?


380) Which of the following is wrong?


381) Which of the following statements is correct?
A. An important characteristic of all communities is that composition and structure constantly change in response to the changing environmental condition.
B. These changes lead finally to a community that is in equilibrium with it self and not the environment and that is called climax community.
C. The entire sequence of communities that successively change in a given area are called sere(s).


382) The two major differences between carbon and phosphorus cycle are -
A. Atmospheric inputs of phosphorus through rainfall are much smaller than carbon inputs.
B. Atmospheric inputs of phosphorus through rainfall are much greater than carbon inputs.
C. Gaseous exchange of phosphorus between organic and environment is not negligible.
D. Gaseous exchange of phosphorus between organic and environment are negligible.


383) With which of four levels of biological organization of Ecology is basically concerned?
A. Organisms
B. Species
C. Family
D. Population
E. Community
F. Biomass


384) Which of the following is in order of importance of the most influencing factor in life of organisms?


385) Which of the following statements are correct?
A. Detritivores break down detritus into smaller particles. This process is called fragmentation.
B. By the process of leaching, water soluble inorganic nutrients go down into the soil horizon and get participated as unavailable salts.
C. Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called catabolism.


386) Which of the following statements regarding decomposition is false?
I. Warm and moist favours decompositions.
II. Decomposition rate is slower if detritus is rich in chitin and lignin.
III. Earthworm is detritus.
IV. Precipitation of soluble inorganic nutrients in the soil horizon as unavailable salt is called mineralization.
V. Detritus is the raw material for decomposition.


387) Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter constitutes


388) Which of the following represents an incomplete ecosystem?


389) Which of the given below pyramids represents the variation in biomass at different trophic levels in pond ecosystem?


390) Choose the odd one out w.r.t. succession


391) Organisms which are associated with first as well as third trophic level are


392) During nutrient immobilization, nutrients get incorporated in the body of living organisms like


393) Net primary productivity


394) The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis is called primary production, which is expressed as


395) Researchers have put an average price tag of US $ 33 trillion a year on the fundamental ecosystems services, which are largely taken for granted because they are free. This is nearly how many times the value of the global gross national product.


396) The overall productivity in terrestrial ecosystems is limited by


397) Productivity at the second trophic level is always


398) Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time?


399) The path that an element takes as it moves from abiotic systems through living organisms and back again is referred to as its


400) Which of the following is not one of the three aspects studied in biogeochemical cycling?


401) Which of the following most often limits the rate at which nutrients move through an ecosystem?


402) Perturbation of which of the following cycles contributes most to global warming?


403) Why are economists trying to quantify the dollar value of ecosystem services?


404) In most food chains,


405) Assume that the green plants in an ecosystem produce 1000 grams of dry mass per square meter par year and there is an efficiency of 10 percent in each transfer of energy from one trophic level to the next. How many total grams of dry mass will produce by the tertiary consumers per square meter per year?


406) The problem(s) with the notion that if all humans became vegetarians, then the earth could support more people is that


407) Of the five elements that are the most important constituents of living things, the only one that requires the action of microorganisms to enter the living system is


408) Relationships in an ecosystem can be depicted through


409) In upright pyramid of biomass, herbivores occupy the position


410) Which one is inverted pyramid?


411) Pyramid of numbers in grassland ecosystem is


412) An ecological pyramid of biomass is the representation of the ecosystem's


413) Both, hydrarch and xerarch successions lead to


414) Mr. X is eating yoghurt. For this he is occupying the trophic level.


415) The breakdown of detritus into smaller particles by earthworm is a process called


416) Which of the following would probably have the greatest total biomass?


417) Which one of the species is probably carnivorous?


418) Which species is (a) decomposer?


419) If a pyramid of number, representing an ecosystem of a large fresh water pond, the number of primary consumers is


420) The free floating organisms of an open sea and the shore are collectively called


421) Which creatures are direct or indirect food of all creatures on the ocean's surface?


422) In plant succession when climax is reached the net productivity


423) In autogenic succession


424) Find out the correct older of succession levels in xerarch.


425) Which one of the following ecosystem types has the highest annual net primary productivity?


426) In a pyramid of number, in a grassland ecosystem, the largest population is that of


427) Some of the stages in the hydrarch are labelled as -
A. Marsh meadow stage
B. Reed swamp stage
C. Submerged plant stage
D. Phytoplankton stage
E. Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages.


428) Which one of the following regarding ecological pyramid is not correct?


429) Consider the following statements concerning food chains.
A. Removal of 80% tigers from an area resulted in greatly increased growth of vegetation.
B. Removal of most of the carnivores resulted in an increased population of deers.
C. The length of food chains is generally limited to 3-4 torphic levels due to energy loss.
D. The length of food chains may vary from 2 to 8 trophic levels.
Which two of the above statements are correct?


430) The bacteria which attack dead animals are


431) Which one of the following is considered as pioneer community in xerarch?


432) A detrivorous animal of economic importance is


433) The dominant second trophic level, in a lake ecosystem is


434) The correct sequence of plants in a hydrosere is


435) Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?


436) Which of the following statements is false?
I. Pyramids of energy and yearly biomass production can never be inverted, since this would violate the laws of thermodynamics.
II. Pyramids of standing crop and numbers can be inverted, since the amount of organisms at any one time does not indicate the amount of energy flowing through the system.
III. There are certain limitations of ecological pyramids such as it does not take into account the same species belonging to two or more trophic levels.
IV. Saprophytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.


437) Read the following statements carefully.
I. Primary succession is a very slow process taking thousands of years for the climax to be reached.
II. Energy at a higher trophic level is always more than at a lower level.
III. Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called fragmentation.
IV. All succession whether taking place in water or on land, proceeds to a similar climax community - the mesic.
Which of the two above statements are correct?


438) In the process of ecological succession, organisms that are present at one stage change


439) Amount of carbon in the environment


440) The four main processes of the water cycle are


441) In recycling of mineral elements within an ecosystem, the responsible direct causal organism are called


442) Animals with a constant body temperature such as mammals and birds require more food than do animals with a changing body temperature such as reptiles and fish. Why?


443) The most energy-efficient method to feed large human populations such as China is to eat


444) A. GFC is major conduit of energy flow in aquatic ecosystem.
B. Food chain maintains stability in an ecosystem by providing alternate organisms at different trophic level.
C. DFC may be connected to GFC.


445) A term biotype means


446) The pyramid of number of a parasitic food chain in forest ecosystem is


447) Which one of the following statements is correct for secondary succession?


448) In terms of percentage of total forest cover, the most abundant type of the forest in India is


449) The rate of formation of new organic matter by rabbit in a grassland, is called


450) The second stage of hydrosere is occupied by plants like


451) The important steps, in the process of decomposition are


452) In an ecosystem, at a particular time standing crop


453) In a pyramid of biomass, if the total dry weight (kg/ml) of primary producers is about 809 it will decrease at teritary consumer level up-to


454) Which one of the following is not a functional unit of an ecosystem


455) The upright pyramid of number is absent in


456) Which one of the following processes during decomposition is correctly described?


457) A sedentary sea anemone gets attached to the shell lining of hermit crab. The association is


458) Natural reservoir of phosphorus is


459) Secondary productivity is rate of formation of new organic matter by


460) The total mass of nutrient matter that makes up the Earth is _______.


461) The net primary productivity of an ecosystem can be viewed as the


462) Which of the following is incorrect?


463) The removal of 'Keystone' species will affect


464) Anthropogenic ecosystems


465) Select the correct statements.


466) The rate of biomass production and the rate of production of organic matter during photosynthesis are called respectively


467) Pick out the correct option from (A) to (D).
A. Primary succession begins in areas where natural communities have been destroyed.
B. Hydrarch succession takes place in water.
C. The climax community is the community that is in near equilibrium with the immediate environment.
D. In newly cooled lava secondary succession occurs.


468) Which one of the following group of organisms can represent every trophic level in a ecosystem?


469) Vertical distribution of different species occupying different levels in a biotic community is known as


470) Secondary succession takes place on/in


471) In an ecosystem the rate of production of organic matter during photosynthesis is termed as


472) Most animals are tree dwellers in a


473) Most animals that live in deep oceanic waters are


474) In which of the following both pairs have correct combination?


475) During ecological succession


476) Which of the following is a characteristic feature of cropland ecosystem?


477) Which of the following would appear as the pioneer organisms on bare rocks?


478) The term ecosystem was coined by


479) The primary producers of the deep-sea hydrothermal vent ecosystem are


480) Ecotone is


481) 'Edge effect' is observed in case of


482) Community dynamics is related to


483) Which ecosystem has the highest gross primary productivity


484) In primary succession in water, the pioneer species are


485) The pyramid of biomass will be inverted in the ecosystem of


486) Large unit of land having different types of plants and animals, is called


487) Which of the following is known as the sedimentary cycle because its reservoir is a sedimentary rock?


488) In ecological succession the communities in near equilibrium with the environment, are called


489) Dried plant parts such as leaves, bark, flowers, etc., and dead remains of animals including faecal matter,
drop over the soil, constitute
I. below ground detritus
II. above ground detritus
III. litter fall
Choose the correct option


490) In the following, there is no difference


491) Consider the following statements about carbon cycle
I. Carbon is released into the atmosphere
II. The atmospheric input of carbon from rainfall is greater
III. Carbon gas is exchanged between organisms and atmosphere during respiration
Which of the statement given above are correct?


492) Ecological pyramids were discovered by


493) Plant successions occurring in a sandy area is


494) An ecosystem is


495) What do ecologists call the transfer of energy that begins with the sun and passes from one organism to
the next in a food chain?


496) Microbes that breakdown the complex organic matter into simple substances like carbon, nitrogen, water,
etc., are


497) Which one of the following is no used for construction of ecological pyramids?


498) Which element is formed by the weathering of rocks and absorbed by plant from the soil?


499) Series of changes in structure and comparition of communities on previously barren area is


500) Energy transferred from on trophic level to another is


501) When the two ecosystems overlap each other, the areas is called


502) The total amount of nutrients like carbon, phosphorus, calcium, etc., present in soil at any time is called


503) A food web is more realistic than a food chain for showing the feeding relationships in an ecosystem
because


504) Which of the following ecological pyramid are always inverted?


505) An individual transitional communities in ecological succession are termed as


506) The living organisms present in an ecosystem forms


507) The rate of biomass production per unit area over a time period by plants during photosynthesis is called


508) The decomposition rate is higher when detritus is rich in


509) A man-made ecosystem is


510) The green plants in an ecosystem which can trap solar energy to convert it into chemical bond energy are
called


511) Vegetable eating person acts as


512) Consider the following statements about food chain
I. The transfer of energy from producers to top consumers through a series of organisms is called food
chain
II. A food chain is always straight and proceeds in a progressive straight line
III. In a food chain, there is unidirectional flow of energy from sun to producers and subsequently to series
of different types of consumers
Which of the statements given above are correct?


513) Consider the following ecosystem
I. Pond ecosystem II. Terrestrial ecosystem
III. Oceans ecosystem IV. Forest ecosystem
There are mainly three food chain in natural ecosystem’s grazing food chain, detritus food chain, parasite
food chain
Find out which of the following will have grazing food chain?


514) A much large fraction of energy flows in aquatic ecosystem through


515) Consider the following statements concerning food chains.
I. Removal of 80% tigers from an area resulted in greatly increased growth of vegetation.
II. Removal of most of the carnivores resulted in an increased population of deers.
III. The length of food chains is generally limited to 3 to 4 trophic levels due to energy loss.
IV. The length of food chains may vary from 2 to 8 trophic levels.
Which two of the above statements are correct?


516) Consider the following statements about food web
I. One organism hold more than one position
II. The flow of energy is very difficult to calculate
III. Instead of straight line it is a series of branching lines
IV. Competition is amongst the members of same and different trophic levels
Which of the statements given above are correct?


517) The statement, ‘Tiger is in the apex of food chain’, indicates


518) Primary productivity is affected by
I. temperature
II. sunlight
III. moisture
IV. availability of nutrients


519) Inverted pyramid is found in


520) If a predator is overexploits its prey in a ecosystem then what might be consequences of this?


521) Which of the following organisms form the decomposers?


522) Osmotrophs belong to


523) Greater primary productivity depends upon


524) Word detritus includes


525) Decomposition of organic matter is brought about by


526) Some of the stages in the hydrarch are labelled as
I. Marsh meadow stage
II. Reed swamp stage
III. Submerged plant stage
IV. Phytoplankton stage
V. Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages


527) The correct sequence of food chain is


528) When the number of organisms at successive levels are plotted they assume the shape of a pyramid. This
is called the pyramid of


529) In ecotone, some species become abundant called


530) Ecosystem may be defined as


531) Phosphorus is required for making
I. shell
II. bones
III. teeth
Choose the correct option


532) The species that invade a bare area in ecological succession are called


533) In a pond ecosystem, benthos means


534) Decomposers are


535) The lentic ecosystem includes


536) Primary succession on rocks starts with


537) True/False
I. The total organic matter synthesised by the producers in the process of photosynthesis per unit time and
area is known as gross primary productivity
II. Net primary productivity is the weight of the organic matter stored by the producers in a unit
area/volume per unit time


538) Lion is kept under in Eltonian pyramid as


539) Maximum primary productivity of pond is achieved by


540) What is the medium by which carbon cycle takes place?


541) …… temperature is required for the proper functioning of an enzyme. The most appropriate word


542) In ecological pyramid the base always represent the …A… and the apex represents …B… Here A and B
represents


543) The primary consumers in a pond ecosystem are


544) Which of the following factor is contributing to an overload of the carbon cycle?


545) Which ones are the reservoirs of sulphur and carbon cycles respectively?


546) Trophic level of food chain having greatest amount of energy, is


547) The entire sequence of communities that successively changes in a given area are called


548) Energy flow in ecosystem is


549) A bear that eats a fish that further ate bugs that ate algae is a


550) Acid secreted lichens on baren rock helps in
I. dissolving rocks
II. weathering
III. soil formation
Which of the statements given above are correct?


551) In an ecosystem, the cycling of nutrient is known as


552) The aquatic organism that can actively swim at will against the water current is


553) Green plants and green sulphur bacteria, prepare their organic food themselves with the help of sunlight,
are known as


554) The movement of nutrient elements through various components (abiotic and biotic) of an ecosystem is
called


555) Biotic community along with its interacting physical environment comprises


556) The relation between producers and consumers in an ecosystem can be graphically represented in the
form of a pyramid called


557) Energy stored at the consumer level is


558) Actively moving organisms in aquatic ecosystem are


559) The secondary succession is easy and is completed quickly, because the area


560) Gross primary productivity is utilised by …A… in …B…
Choose the correct option for A and B


561) What will happen if all the bacteria and fungi are destroyed?


562) Abiotic components refers to


563) Which of the following ecological pyramids can never occur in an inverted from


564) Identify the correct type of food chain.
Dead animal → Blow fly maggots → Common frog → Snake


565) Ecosystem is


566) Which of the following pair is a sedimentary type of biogeochemical cycle?


567) Tropical dense forests are due to


568) In a lake, phytoplankton grow I abundance in


569) At each step of food chain when food energy is transferred from one trophic level to the next higher
trophic level only about 10% of energy is passed onto next level. This is known as …A… given by …B… in
…C… . Here A, B and C Refers to


570) The process of accumulation of a dark coloured amorphous substance that is highly resistant to microbial
action and undergoes decomposition at an extremely slow rate is called


571) Total energy fixed by an ecosystem is called


572) A detrivore is


573) All the animals that depend on plants for food are called


574) Out of the following biogeochemical cycles which one is gaseous?
I. sulphur II. Phosphorus
III. nitrogen IV. Carbon
Choose the correct option


575) In a food chain, the maximum population of


576) Overlapping region between two ecosystems is called


577) The major functions of an ecosystem includes
I. productivity II. Decomposition
III. energy flow IV. Nutrient flow
Choose the correct option


578) In grazing food chain energy comes from


579) Which one of the following is correct for xerarch succession?


580) Biotic components refer to


581) Which one of the following is correct matching of a plant, its habitat and the forest type where it normally
occurs?


582) What is common in earthworm, soil mites and dung beetle in an ecosystem?


583) Which one of the following is involved in sedimentary cycle?


584) Which of the following pyramid is always upright and can never be inverted?


585) The 10% law is related to


586) Which of the following two organisms are producers?


587) Consider the succession of plants
I. In hydrarch succession series progress from hydric to the mesic condition
II. In xerarch succession series progress from xerarch to the mesic condition
III. In xerarch succession if it is started on bare rock the pioneer species is lichens
IV. In hydrarch and xerarch succession series progress from mesarch to xerarch condition
Which of the following is correct combination match from above statements?
Choose the correct option


588) An inverted pyramid of …A… may occasionally be observed in …B… communities


589) Which one of the following is not a functional unit of an ecosystem?


590) Which one of the following types of organisms occupy more than one trophich level in a pond ecosystem?


591) Humus is


592) In terrestrial ecosystem such as forest, maximum energy is found in which tropic level?


593) Frog, that feeds on insects, is a


594) The organisms, which attack dead animals are


595) Pyramid of energy in aquatic ecosystem is


596) Consider the following statements about ecological pyramids
I. Charles Elton developed the concept of ecological pyramid
II. After the name these pyramids are also called as Eltonian pyramids
III. It is a graphical representation or pyramid shaped diagram which depicts the number of organisms,
biomass and energy at each trophic level
Which of the statements given above are correct?


597) Which of the following pyramid of numbers in ecology is not upright?


598) A lion that eats a zebra that ate grass is a


599) Pyramids of biomass in pond ecosystem is


600) The process of which humus is degraded by some microbes to release inorganic nutrients is known as


601) The process of mineralisation by microorganisms helps in the release of


602) Which of the following plants develop characters of xerophytes?


603) Which one of the following statements is correct for secondary succession?


604) Phytoplanktons are found in which of the following zones?


605) The role of a cow in a food chain is


606) Consider the following statements about limitations of ecological pyramids
I. It never takes into account the same species belonging to two or more trophic levels
II. It assumes a simple food chain, which never exists in nature
III. In split of the vital role played by saprophytes/decomposers, they are not given any position in
ecological pyramids
Which of the statements given above are correct?


607) Which of the following always has a pyramidal shape, that is, decreasing values at higher trophic levels?


608) Identify the plant belonging to the reed-swamp stage in hydrarch succession


609) Secondary productivity is


610) Extinction of a species in a food chain is compensated by


611) The changes that occur in successive seral stages to reach a climax community are
I. changes in the diversity of species of organisms
II. increase in the number of species and organisms
III. increase in the total biomass
Choose the correct option


612) Which one of the following is a gaseous cycle?


613) Which of the following statements are correct?
I. Least productive ecosystems are deserts and deep lakes
II. Sugarcane is the most productive crop
III. Most productive ecosystem is coral reef
Choose the correct option


614) Pyramid of energy in ecosystem is


615) A plant is


616) Ecosystem having the highest primary productivity is


617) The Great Barrier Reef along the east coast of Australia can be categorized as


618) A much smaller fraction of energy flows in a terrestrial ecosystem through


619) …A… is required for higher primary productivity. …B… have the lowest primary productivity as the soil is
deficient in moisture.
Choose the correct option for A and B


620) Driving force of any ecosystem is


621) Climax community is


622) Stratification occurs in


623) Regarding 10% law
I. This law was put forward by Lindeman in 1942
II. According to this law, during the transfer of food energy from one tropical level to the other, only about
10% is stored at higher trophic level and the remaining 90% is lost in respiration, decomposition and
waste in the form of heat
Which of the statements given above is/are correct?


624) Ecological succession is a


625) At which latitude, heat gain through insolation approximately equals heat loss through terrestrial
radiation?


626) Rabbits eats grass and other plants to survive, but they do not eat animals. Refer the best category for
rabbits?


627) To show how many organisms are present at each level of a food chain, ecologists use a model called


628) Competition for food, light and space is most severe between two


629) The reservoir for the gaseous type of biogeochemical cycle exists in


630) Autotrophs


631) An ecosystem, which can be easily damaged but can recover after some time if damaging effect stops, will
be having


632) Which of the following ecosystem types has the highest annual net primary productivity?


633) In pond ecosystem, diatoms represent


634) Two species occupying same or overlapping area are called as


635) Choose the area which will take minimum time for succession


636) Each tropical level has a certain mass of living material at a particular time called


637) The process by which water soluble inorganic nutrients go down into the soil horizon and get precipitated
as unavailable salts is called as


638) The nature of climax community in ecological succession in most dependent upon


639) Group of two or more than two plant species is called as


640) The products of decomposition process are


641) The reservoir for the sedimentary cycle exists in


642) Standing crop refers to


643) Vertical distribution of different species occupying different levels in an ecosystem is called


644) Fill in the missing stages (A to D) in the given primary hydrarch succession.
Phytoplankton → (A) → (B) → (C) → Marsh-meadow stage → (D) → Forest plant stage


645) A community that starts the process of succession in a barren habitat is called


646) How much incident sun radiation on earth is utilised by producers (plants)?


647) Percentage of Photosynthetically Active Radiation (PAR) that is captured by plants in synthesis of organic
matter is


648) The term ‘homeostasis’ in an ecosystem refers to


649) Trophic level in ecosystem is formed by


650) Which one of the following is a sedimentary cycle?


651) Select the matched ones.
I. Sedimentary nutrient - Nitrogen cycle
II. Pioneer species - Lichens
III. Secondary succession - Burned forests
IV. Pyramid of biomass in sea - Upright


652) Which of the following is an example of man-made ecosystem?


653) The sunlight directly regulates the primary productivity because


654) What is the reason behind deficit rising in nutrient reservoir?


655) “Complete competitiors cannot coexist” is true for


656) In a comparative study of grassland ecosystem and pond ecosystem, it may be observed that


657) Food chain refers to


658) A person who eats a chicken that ate grain is a


659) Pyramid that is never inverted


660) Major ecological community of plants and animals extending over large natural areas is known as


661) In a pyramid of numbers in a grassland ecosystem, the largest population is that of


662) The exchange pool in the carbon cycle is


663) Primary productivity is
I. is 10% less than secondary productivity
II. is the rate of formation of new organic matter by consumers
III. is expressed in terms of weight or energy
IV. is the amount of biomass or organic matter produced per unit area over a time period in plants during
photosynthesis
Which of the statements given above are correct?


664) Which of the following is false?


665) These belong to the category of primary consumers


666) Total amount of living material at the various trophic level of a food chain is depicted by pyramids of


667) Primary productivity depends upon


668) Consider the following statements
I. Producer are also called as transducers because they are able to change radiant energy into chemical
form
II. Consumers are animals, which feed on other organisms or their parts III. Decomposers are saprotrophs, which feed on dead bodies of organisms
Which of the statements given above are correct?


669) Only a small amount of the energy stored in food is available to the next organism in a food chain because


670) The process of accumulation of a dark coloured …A… substance called …B… that is highly resistant to
microbial action and undergoes decomposition at an extremely slow rate is called …C…
Choose the correct option for A, B and C


671) In autogenic succession,


672) The average trophic efficiency of transfer of energy from one trophic level to the higher trophic level is
called


673) The two components of an ecosystem are


674) The food chain which begin with dead organic matter is called


675) The rate of formation of new organic matter by rabbit in a grassland is called


676) The sequence of communities showing a gradual change in composition is called


677) Which of the following is the logical sequence of primary succession in water?


678) In an aquatic ecosystem, the trophic level equivalent to cows in grasslands is


679) Energy for the detritus food chain comes from


680) The organic substance, which decompose slowly are


681) Stability of ecosystem depends upon


682) Mr. X is eating curd/yoghurt. For this food intake in a food chain, he should be considered as occupying


683) A pyramid of number in grassland ecosystem shows


684) Phosphorus is needed for the production of


685) Which of the following statement is true about ecosystem?


686) Which food chain correctly describes the flow of energy in an ecosystem?


687) Phosphorus is the major constituent of
I. biological membranes
II. nucleic acids
III. cellular energy transfer system
Choose the correct option


688) The biomass available for consumption by the herbivores and the decomposers is called


689) In a grazing food chain carnivores may also the referred to as


690) In a food chain, the total amount of living material is depicted by


691) In an ecosystem, the insectivorous plants are placed in


692) Find the correct statement


693) The rate of which organic compounds are formed in a green plant or in a population of green plants per
unit time and area is known as the


694) The correct sequence of plants in a hydrosere is


695) A sequence of species or organism through which the food energy pass in a community is called


696) Select the formula for ecological efficiency.


697) A functional aspect of an ecosystem is


698) Consider the following statements
I. In a food chain one organism holds only one position
II. In a food chain the flow of energy can be easily calculated
III. In food chain competition is limited to the members of same trophic level
Which of the statements given above are correct?


699) What is the percentage of Photosynthetically Active Radiation (PAR), if incident solar radiation is
considered 100%?


700) Choose the wrong pair.


701) Which is an example of true pyramid in an ecosystem?


702) The 10% energy transfer law of food chain was given by


703) In plant succession, when climax is reached, the net productivity


704) The transition zone between two communities is known as


705) Primary productivity is


706) In food chain, maximum energy is stored in


707) Consider the following statements about pyramid of biomass
I. When we plot the biomass (net dry weight) of producers, herbivores, carnivores and so on we have a
pyramid of biomass
II. Two types of pyramid of biomass are found, i.e., upright and inverted
III. When larger weight of producers support a smaller of biomass weight of consumers an upright
pyramid results
IV. When smaller weight of producers support larger weight of consumers an inverted pyramid of biomass
is formed
Which of the statements given above are correct?


708) The final stable community in ecological succession is


709) In what order do a hawk, grass and rabbit form a food chain in a meadow?


710) What is the amount of carbon fixed in biosphere through photosynthesis annually?


711) Find out the correct order of succession levels in xerarch.


712) In the phosphorus cycle, weathering makes phosphate available first to


713) Which of the following is wrongly matched?


714) The factors influencing the rate of decomposition are


715) Decomposers like fungi and bacteria are
I. autotrophs
II. heterotrophs
III. saprotrophs
IV. chemoautotrophs
Choose the correct option


716) Which of the following groups is absolutely essential functional component of the ecosystem?


717) Lichens that start the succession on a rock belongs to


718) Peacock eats a snake and snake eats frog and frog eats insect while insect eats green plant, the position of
peacock is


719) The enzymatic process by which degraded detritus is converted into simpler inorganic substances is called


720) Consider the following statements
I. The pyramid of biomass is inverted in a pond ecosystem
II. Pyramid of energy is never inverted
III. Pyramid of number is inverted in a tree ecosystem
IV. Pyramid of biomass in forest ecosystem is upright
Which of the statements given above are correct?


721) Plants which are attached to the rocks are called


722) The ecological pyramid that is always upright


723) The sequential, gradual and predictable changes in the species compositions in an area are called


724) Food chain is a series of population, which starts with producers. It is concerning with


725) One model that shows how energy passes from one trophic level to another trophic level is called


726) In an ecosystem, in which an organism occupies a specific place in a food chain


727) All are true for climax community except


728) Excessive moisture inhibit the process of decomposition due to


729) Select the true statements
I. Gross primary productivity is equal to the net primary productivity minus respiration
II. Gross primary productivity is equals to net primary productivity plus photosynthesis
III. Net primary productivity is equal to photosynthesis plus respiration
IV. Net primary productivity is equal to gross primary productivity minus respiration
V. Flow of energy in an ecosystem is unidirectional


730) Which of the following statements regarding food chain is false?


731) Phytoplanktons


732) Which of the following pair is a gaseous type of biogeochemical cycle?


733) Which zone of a lake has no photosynthetic organism?


734) The second stage of hydrosere is occupied by the plants like


735) If a single plant species is removed from a food web, then most likely


736) Fungi in a forest ecosystem is


737) The ultimate energy source of ecosystem is


738) Lichen is the pioneer vegetation on which succession?


739) Benthic organisms are found in


740) Organisms that breakdown the detritus into matter particles are


741) The assemblage of all the population of different species that function as an integrated unit through
coevolved metabolic transformation in a specific area is called


742) The organisms which physically and chemically breaks the complex dead organic remains are known as


743) Which of the following helps in the growth of terrestrial pteridophytes in tropical rain forest?


744) Which one of the following shows detritus food chain?


745) Energy enters the ecosystem through


746) Deserts, grasslands, forests and tundra are the examples of


747) Decomposers of an ecosystem includes


748) The pyramid of energy is always upright for any ecosystem. This situation indicates the fact that


749) Term ‘ecosystem development’ to ecological succession was given by


750) Organisms are classified into trophic levels according to


751) The tiger biomass is 10 kg in grass-deer-tiger food chain. The grass biomass will be


752) Study the four statements (I-IV) given below and select the two correct ones out of them
I. A lion eating a deer and a sparrow feeding on grain are ecologically similar in
being consumers.
II. Predator star fish Pisasterhelps in maintaining species diversity of some invertebrates.
III. Predators ultimately lead to the extinction of prey species.
IV. Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders.


753) Building of biomass or storage of energy by green plants in a unit time and area is called


754) Sal and teak are dominant in


755) Rate of conversion of light energy into chemical energy of organic molecules in an ecosystem is


756) What percentage of heabivore’s chemical energy is transferred to the chemical energy within the carnivore
tissue?


757) In which layer of soil decomposition occurs at maximum rate?


758) Term ‘ecosystem’ was given by


759) Most diverse organisms of an ecosystem are


760) Primary succession is the development of communities on


761) Select the incorrect food chain


762) Which one of the following correctly represents as organism and its ecological niche?


763) The pyramid of number of a parasitic food chain in tree ecosystem is


764) Stratification is more pronounced in


765) What is true about the phosphorus cycle?
I. Rocks are the natural reservoirs of phosphorus
II. Weathering of sedimentary rocks makes phosphate available to the soil
III. Herbivores and carnivores obtain phosphorus from plant directly or indirectly
Choose the correct option


766) How much carbon is dissolved in the oceans?


767) The greatest biomass of autotrophs in the world’s oceans is that of


768) Which one of the following is commonly found in temperate coniferous forests?


769) Littoral zone is located along the


770) Biological equilibrium is found among the


771) Net primary productivity is utilised by


772) Which of the following is the logical sequence of primary succession in rocks?


773) Another name of nutrient cycling is


774) Which one of the following statements for pyramid of energy is incorrect, whereas the remaining three are
correct?


775) Transition zone between two ecosystems is


776) Statement 1: A network of food chains existing together in an ecosystem is known as a food web.
Statement 2: An animal like kite cannot be a part of a food web.


777) Statement 1: In a food chain members of successive higher levels are fewer in number.
Statement 2: Number of organisms at any trophic level depends upon the availability of organisms,
which serve as food at the lower level.


778) Statement 1: Nutrient cycle means the cycling of glucose or reserved food material within the plant
body
Statement 2: Transfer of biogenetic nutrients between living and non-living components is called
biogeochemical cycle


779) Statement 1: Oceans acts as the global sink for CO2
Statement 2: Human activities are increasing CO2 concentration in the air


780) Statement 1: Herbivores are also called as first order consumers
Statement 2: Herbivores obtain their food directly from plants


781) Statement 1: Tropical rain forests are disappearing fast from developing countries such as India.
Statement 2: No value is attached to these forests because these are poor in biodiversity


782) Statement 1: True xerophytes store water in the form of mucilage which helps to withstand prolonged
period of drought.
Statement 2: Vascular and mechanical tissues are well developed in true xerophytes.


783) Statement 1: The pyramid of number of pond ecosystem is upright
Statement 2: Phytoplanktons are maximum and secondary consumers are least in number


784) Statement 1: The pyramid of energy is always upright
Statement 2: Number of autotrophs in the pyramid of energy are maximum


785) Statement 1: Ecological succession can turn a lake into a dryland forest with time
Statement 2: A bare rock can become a forest through ecological succession


786) Statement 1: An ecosystem is an interaction between biotic and abiotic components
Statement 2: AG Tansley coined the term ecosystem


787) Statement 1: Bacteria and fungi are microconsumers
Statement 2: Bacteria and fungi use a very little part of living plant and animals


788) The ecological niche of population is a


789) Energy flow and energy transformation in living systems strictly conform to the


790) Which one of the following pairs is mismatched?


791) Regarding the mode of obtaining food, the organisms occurring in an ecosystem are classified into plants,
animals and microorganisms. These are respectively called


792) The amount of living matter present in an ecosystem at a given time is called


793) Most diverse organism of an ecosystem is


794) Plant species having a wide range of genetical distribution evolve into a local population known as


795) If we completely remove the decomposers from an ecosystem, its functioning will be adversely affected
because


796) Energy transfers or transformation are never 100% efficient. This is due to


797) Nektons are


798) Which of the following communities is more vulnerable to invasion by outside animals and plants?


799) ‘Sun basket’ is


800) Detritus food chain law accounts for more energy flow than garzing food chain because


801) Primary consumers are


802) The minimum number of components required for an ecosystem to survive


803) In plant succession, when climax community is reached, the net productivity


804) Pond is defined as a


805) Niche is defined as the


806) Most stable ecosystem is


807) Community is a group of independent and interacting population of


808) Pollution caused by persistent pesticides is relatively more hazardous to which type of organisms?


809) If decomposers are removed what will happen to the ecosystem?


810) Organisms living in open sea are called


811) Which one of the following is one of the characteristics of a biological community?


812) Broad-leaved forests of oak are found in