The following graph depicts changes in two populations (A and B) of herbivores in grassy field. A possible reason for these changes is that

1. both plant populations in this habitat decreased

2. population-B competed more successfully for food than population-A

3. population-A produced more offspring than population-B

4. population-A consumed the members of population-B

Just as a person moving from Delhi to Shimla to escape the heat for the duration of hot

summer, thousands of migratory birds from Siberia and other extremely cold Northern

regions move to

1. Western Ghat               

2. Meghalaya

3. Corbett National Park     

4. Keoladeo National Park

Consider the following four conditions (I-IV) and select the correct pair of them as adaptation to environment in desert lizards.
The conditions:
I.  Burrowing in soil to escape high temperature
II. Losing heat rapidly from the body during high temperature
III. Bask in sun when temperature is low
IV. Insulating body due to thick fatty dermis

1. (I) and (III)
2. (II) and (IV)
3. (I) and (II)
4. (III) and (IV)

What type of human population is represented by the following age pyramid?

1. Stable population

2. Declining population

3. Expanding population

4. Vanishing population

Which one of the following is categorised as a parasite in true sense?

Study the four statements (1-4) given below and select the two correct ones out of them.

(1) A lion eating a deer and a sparrow feeding on grain are ecologically similar in being

consumers

(2) Predator star fish Pisaster helps in maintaining species diversity of some invertebrates

(3) Predators ultimately lead to the extinction of prey species

(4) Production of chemicals such as nicotine, strychnine by the plants are metabolic

disorders

The two correct statements are

1. (2) and (3)               

2. (3) and (4)

3. (1) and (4)               

4. (1) and (2)

A country with a high rate of population growth took measures to reduce it. The figure below shows age sex pyramids of populations. A and B twenty years apart. Select the correct interpretation about them.

Interpretations

1. 'A' is more recent and shows slight reduction in the growth rate

2. 'B' is earlier pyramid and shows stabilized growth rate

3. 'B' is more recent showing that population is very young

4. 'A' is the earlier pyramid and no change has occured in the growth rate  

Consider the following four statements (i-iv) about certain desert animals such as

kangaroo rat.

(i) they have dark colour and high rate of reproduction and excrete solid urine.

(ii) they do not drink water, breathe at a slow rate to conserve water and have their

body

covered with thick hairs.

(iii) they feed on dry seeds and do not require drinking water

(iv) they excrete very concentrated urine and do not use water to regulate body

temperature.

Which two of the above statements for such animals are true?

1. iii and iv

2. ii and iii

3. iii and i

4. i and ii

The formula for exponential population growth is :-

1. dt/dN = rN

2. dN/rN = dt

3. rN/dN = dt

4. dN/dt = rN

Annual migration does not occur in the case of:

1. Salmon

2. Siberian crane

3. Salamander

4. Arctic tern