NEET Ecology & Organisms Practise Questions
1. Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example.
(a) Colour change in Chamaeleon
(b) Enlargement of body size by swallowing air in puffer fish
(c) Poison fangs in snakes
(d) Melanism in moths
2. The niche of a population is the
(a) set of conditions that it interacts
(b) place where it lives
(c) set of conditions and resources it uses
(d) geographical area that it covers.
3. Different biomes are formed due to annual variations in
_____over the earth’s surface.
(a) temperature (b) precipitation
(c) incident solar radiation
(d) all of these
4. Two different species cannot live for long duration in the same niche or habitat. This law is
(a) Allen’s law (b) Gause’s hypothesis
(c) Dollo’s rule (d) Weismann’s theory.
5. Which of the following statements holds true for regulators?
(a) Regulators possess a constant internal environment.
(b) Regulators consume a large amount of energy.
(c) The body fluids of regulators have fixed osmotic concentrations.
(d) All of these.
6. What type of human population is represented by the following age pyramid?
(a) Increasing population
(b) Stable population
(c) Declining population
(d) Expanding population
7. In the given figure, identify the temperate forest and coniferous forest respectively from the markings A–F and select the correct option.
a) A and B (b) B and D
(c) D and E (d) C and F
8. Territoriality occurs as a result of
(a) parasitism (b) co-operation
(c) predation (d) competition.
9. In the sigmoid growth curve given below, the alphabets indicate the sequence of events. Choose the correct option where the alphabet specifies the event.
(a) A = phase of slow growth
B = phase of exponential growth
C = phase of diminishing growth
D = stationary phase
(b) A = phase of rapid growth
B = phase of diminishing growth
C = stationary phase
D = phase of slow growth
(c) A = diminishing growth
B = exponential growth
C = slow growth
D = stationary growth
(d) A = stationary phase
B = phase of slow growth
C = phase of rapid growth
D = phase of diminishing growth
10. An association between two different organisms in which one is always benefitted while the other remains unharmed is
11. Penicillium does not allow the growth of bacterium Staphylococcus. This sort of relationship is called
12. Populations termed r-strategists
(a) are usually pioneer species
(b) have J-shaped growth curves
(c) have type III survivorship curve
(d) all of the above.
13. The carrying capacity of a population is determined by its
(a) limiting resource (b) birth rate
(c) death rate (d) all of these.
14. A plant that grows inside a plant of another species symbiotically is called (a) a semiparasite
(b) a parasite
(c) an endophyte
(d) a saprophyte.
15. The inherent maximum capacity of an organism to reproduce or increase in number is termed
(a) carrying capacity
(b) biotic potential
(c) reproductive health
(d) intrinsic rate of increase.
True or False
16. A population with large number of reproductive and comparatively lesser number of pre-reproductive individuals shows a negative growth rate.
17. Most mammals and birds are stenothermal organisms as they can tolerate a wide range of temperature variations.
18. The body temperature of endothermic animals varies with temperature of the environment.
19. Hydrophytes possess aerenchyma or air storing parenchyma to support themselves in water.
20. Seeds of Viscum are positively photoblastic as they germinate only in presence of light.
21. Loam soil is best suited for plant growth as it contains a mixture of silt, sand and clay.
22. The process of humification is slow in case of organic remains containing a large amount of lignin and cellulose.
23. Hygroscopic water is the only soil water available to roots of plant growing in soil as it is present inside the
24. Regulators perform homeostasis mostly through thermoregulation and osmoregulation by physiological adjustments.
25. Shade plant leaves have more total chlorophyll per reaction centre, low ratio of chl a to chl b and are usually thinner than sun plant leaves.
26. Match Column I with Column II
27. Match Column I with Column II. (There can be more than one match for items in Column I).
Passage Based Questions
28.(A) Complete the given passages with appropriate words or phrases.
(a) (i) is resemblance of one species with another to obtain protection against predation. The species which is imitated is called (ii) while the species which imitates is known as (iii) . (b) In (iv) age pyramid, the number of (v) individuals is higher than the number of (vi) individuals. It indicates (vii) population.
(B) Read the given passage and correct the errors, wherever present.
Parasitism is an interaction between two living organisms of same species in which one called host obtains its food directly from the other called parasite. Endoparasites are temporary parasites which live in the body of host and respire aerobically e.g., lice. Ectoparasites are temporary or permanent parasites which live on the surface of host and respire anaerobically, e.g., Taenia.
Assertion & reason
29. Assertion : Atriplex can grow in saline soil.
Reason : Atriplex is a succulent that possesses salt glands for excretion of salt.
30. Assertion : Small sized animals do not occur in polar regions.
Reason : Small animals have large surface areas as compared to body volumes and tend to lose heat very fast in cold regions.
31. Assertion : Mycorrhiza is a mutualistic association of plant roots with fungi.
Reason: Mycorrhiza is useful in retrieval of critical elements and absorption of water from soil.
32. Assertion : In Batesian mimicry, the mimic is defenseless and resembles a dangerous or unpalatable model.
Reason : Viceroy butterfly which mimics unpalatable and toxic monarch butterfly exemplifies Batesian mimicry.
33. Assertion : Some sea animals protect themselves from excessive cold by developing cold hardiness.
Reason : Cold hardiness is achieved by developing extra solutes in the body fluids and special ice nucleating proteins in the extracellular spaces.
34. Assertion : The association of epiphytes with larger plants is an example of commensalism.
Reason : Epiphytes grow on larger plants and derive nutrition from them using their haustoria.
35. Assertion : Age pyramid for expanding population is broad at the base and gradually tapers towards apex.
Reason : In an expanding population, the number of pre-reproductive individuals is very large, whereas reproductive individuals are moderate and postreproductive individuals are fewer.
36. Assertion : Mortality refers to the number of births per unit population per unit time.
Reason : Mortality increases population density.
37. Assertion : Exponential growth occurs when the resources are abundant.
Reason : Population growing exponentially, seldom grows beyond the carrying capacity of ecosystem.
38. Assertion : Competition always results in extinction of species.
Reason : Two competing species can never coexist
Figure Based Questions
39. Refer the given graph and answer the following questions.
(a) What do curves ‘A’ and ‘B’ represent in the given graph?
(b) What does K represent in the given graph?
40. Refer the given age pyramids (A and B).
Which of the above age pyramids represents a declining population? Give reasons for your answer.
1. (c) 2. (c) 3. (d) 4. (b) 5. (d)
6. (b) 7. (c) 8. (d) 9. (a) 10. (b)
11. (c) 12. (d) 13. (a) 14. (c) 15. (b)
17. False. Most mammals and birds are eurythermal organisms as they can tolerate wide range of temperature variations.
18. False. The body temperature of ectothermic animals varies with temperature of environment.
19. True 20. True
21. True 22. True
23. False. Capillary water is the only water available to plant
roots as it is present inside the micropores.
24. True 25. True
26. A-(iii), B-(iv), C-(i), D-(ii), E-(v)
27. A-(iv, v), B-(i, vi), C-(ii,vii), D-(iii, viii), E-(ix, x)
28.(A) (a) (i) Mimicry (ii) model
(b) (iv) urn-shaped (v) reproductive
(vi) pre-reproductive (vii) declining
(B) Parasitism is an interaction between two living organisms of different species in which one called parasite obtains its food directly from the other called host. Endoparasites are permanent parasites which live in the body of host and respire anaerobically e.g., lice Taenia. Ectoparasites are temporary or permanent parasites which live on the surface of host and respire aerobically, e.g., lice.
29. (a) 30. (a) 31. (b) 32. (b) 33. (b)
34. (c) 35. (a) 36. (d) 37. (c) 38. (d)
39. (a) In the given graph, curve ‘A’ represents population growth when resources are not limiting the growth, i.e., the population grows in an exponential or geometric ratio. Curve ‘B’ represents population growth when resources are limiting the growth i.e., the population shows logistic growth.
(b) In the given graph, K represents carrying capacity. In nature, a given habitat has resources to support a certain number of individuals of a population, beyond which no further growth is possible. This limit is called carrying capacity (K) of habitat for that species.
40. Age pyramid B, represents a declining population, i.e., a population with negative growth. This can be explained as follows:
The base of an age pyramid always represents the number of pre-reproductive individuals whereas reproductive individuals are placed above pre-reproductive individuals. Post-reproductive individuals occupy the apex of age pyramid. The age pyramid A is triangular shaped with broad base which gradually tapers towards apex. This indicates that the number of pre-reproductive individuals is higher than reproductive individuals. Post-reproductive individuals are even fewer. This is the characteristic of growing population. Age pyramid B is urn-shaped where base is narrower than the upper portion which gradually tapers towards apex. Here the number of reproductive individuals is higher than pre-reproductive individuals and post-reproductive individuals are sizeable. This condition is indicative of declining population.
18. False. Standing state is the amount of inorganic nutrients
present in an ecosystem.
19. False. The amount of organic matter stored by producers per
unit time per unit area is called net primary productivity.
20. True 21. True 22. True 23. True
24. False. In a hydrosere, sedge meadow stage is inhabited
by plants like Carex and Juncus etc., whereas Typha and
Scirpus occur in reed swamp stage.
26. A-(iii), B-(i), C-(ii), D-(v), E-(iv)
27. A-(v, vi), B-(i, vii), C-(ii,viii), D-(iii, ix), E-(iv, x)
28.(A) (a) (i) nudation (ii) invasion
(b) (iv) Primary succession (v) bare rock
(vi) slow (vii) Secondary succession
(viii) cut over forest
(B) Energy flow in an ecosystem is always unidirectional. There is decrease in the content and flow of energy with rise in trophic level. Maximum energy content is present in producers. The pyramid of energy is always upright.
29. (a) 30. (a) 31. (a) 32. (b) 33. (b)
34. (b) 35. (c) 36. (d) 37. (c) 38. (b)
39. (a) X – Decomposition,
Y – Weathering
(b) Phosphorus is mostly used as phosphate. Small amount of phosphate is always being added to cycling pool (soil) through weathering of rocks. In soil, phosphate is generally found in combination with calcium, iron and aluminium. Decomposers present in soil also add phosphate to it by the process of decomposition of detritus.
40. (a) (1) grasshopper, (2) deer, (3) fox, (4) snake (b) There are 5 primary consumers (deer, rat, rabbit, grasshopper and sparrow) and 3 top consumers (owl, lion and hawk) in the given food web.