| I. | migrate temporarily | 
| II. | suspend their development till the return of favourable conditions | 
| III. | become ‘regulators’ if they are ‘conformers’ | 
| Statement I: | Bears go into aestivation to avoid summer related problems – heat and dessication. | 
| Statement II: | Snails and fish go into hibernation during winter. | 
| I. | Many adaptations have evolved over a long evolutionary time and are genetically fixed. | 
| II. | Kangaroo rat has a remarkable ability to concentrate its urine. | 
| III. | In Opuntia, leaves are reduced to spines and the photosynthetic function is taken over by the flattened stems. | 
| Assertion (A): | Tribes living in high altitudes of Himalayas normally have a higher RBC count [or total haemoglobin] than people living in the plains. | 
| Reason (R): | In low atmospheric pressure of high altitudes, the hypoxic conditions lead to an increased production of RBCs by bone marrow. | 
| 1. | Both (A) and (R) are true and (R) explains (A). | 
| 2. | (A) is true but (R) is false. | 
| 3. | (A) is false but (R) is true. | 
| 4. | Both (A) and (R) are true but (R) does not explain (A). | 
| Assertion (A): | Population ecology links ecology to population genetics and evolution. | 
| Reason (R): | It is at the population level that natural selection operates to evolve the desired traits. | 
| 1. | Both (A) and (R) are True and (R) explains (A). | 
| 2. | Both (A) and (R) are True but (R) does not explain (A). | 
| 3. | (A) is True but (R) is False. | 
| 4. | (A) is False but (R) is True. | 
| I. | The ecological role of the banyan tree in this community is negligible when compared to that of carrot grass. | 
| II. | In this community, the percent cover or biomass is a more meaningful measure of the population size. | 
| Assertion (A): | The number of fish caught per trap is not a good measure of its total population density in the lake. | 
| Reason (R): | For ecological investigations, it is obligatory to count every individual in a population to estimate population density. | 
| 1. | Both (A) and (R) are True but (R) does not explain (A). | 
| 2. | Both (A) and (R) are False. | 
| 3. | Both (A) and (R) are True and (R) explains (A). | 
| 4. | (A) is True but (R) is False. | 
| I. | Nt+1 = Nt + [(B+I) – (D+E)] | 
| II. | B is a measure of Natality and D is a measure of Mortality | 
| III. | If (B+I) is less than (D+E), the population density will increase | 
| 1. | Only I and II are correct | 2. | Only I and III are correct | 
| 3. | Only II and III are correct | 4. | I, II and III are correct | 
| I | B | D | E | |
| 1. | Emigration | Natality | Mortality | Immigration | 
| 2. | Emigration | Mortality | Natality | Immigration | 
| 3. | Immigration | Natality | Mortality | Emigration | 
| 4. | Immigration | Mortality | Natality | Emigration | 
| Assertion (A): | The logistic growth model is more realistic for most animal populations in nature. | 
| Reason (R): | Resources for growth for most animal populations are finite and become limiting sooner or later in the nature. | 
| 1. | (A) is True but (R) is False. | 
| 2. | Both (A) and (R) are True and (R) correctly explains (A). | 
| 3. | (A) is False but (R) is True. | 
| 4. | Both (A) and (R) are True but (R) does not explain (A). |