Question 1

Match List-I with List-II . List-I List-II A. Both species are harmed I. Predation B. One species is harmed and the other is benefited II. Mutualism C. Both species are benefited III. Competition D. O

Accepted Answer

In competition, both interacting species are harmed as they compete for the same limited resources. Thus, A matches III. In predation, one species (predator) benefits while the other (prey) is harmed. Thus, B matches I. In mutualism, both interacting species benefit from each other. Thus, C matches II. In commensalism, one species benefits while the other is neither harmed nor benefited (no effect). Thus, D matches IV. The correct matching is A-III, B-I, C-II, D-IV.

Question 2

Choose the correct statements regarding population interactions between two species. A. In both parasitism and commensalism, only one species benefits and the other species is harmed. B. Both species

Accepted Answer

In mutualism, both species benefit from the interaction (+, +). In commensalism, one species benefits and the other is neither harmed nor benefited (+, 0). In parasitism, one species benefits and the other is harmed (+, -). In amensalism, one species is harmed and the other is unaffected (-, 0). Therefore, statements B, D, and E are correct. Answer: B, D and E only

Question 3

Which of the following equations depicts Verhulst-Pearl logistic population growth ?

Accepted Answer

The Verhulst-Pearl logistic population growth is described by the equation: dN dt = rN ( K-N K ) where N is the population density at time t, r is the intrinsic rate of natural increase, and K is the carrying capacity. Answer: dN dt = rN ( K-N K )

Question 4

Consider a population of 10 million cells. Given the per-capita birth rate of 0.002 (per unit time) and the per-capita death rate of 0.002 (per unit time), the expected number of cells after 10 genera

Accepted Answer

Given initial population N_0 = 10 million. Per-capita birth rate b = 0.002. Per-capita death rate d = 0.002. The intrinsic rate of natural increase r is given by r = b - d. r = 0.002 - 0.002 = 0. The population growth equation is N_t = N_0 e^ rt . Substituting r = 0, we get N_t = N_0 e^0 = N_0. Thus, the population size remains constant over time. The expected number of cells after 10 generations is 10 million. Answer: 10 million

Question 5

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : The logistic growth model of populations is considered more realistic than the exp

Accepted Answer

The exponential growth model assumes that resources are unlimited, which allows a population to grow continuously at a constant rate. However, in nature, resources such as food, space, and water are finite and eventually become limiting factors for population growth. The logistic growth model incorporates these limiting factors and introduces the concept of carrying capacity, which is the maximum population size that an environment can sustain indefinitely. Because it accounts for the finite nat

Question 6

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : Abingdon tortoise in Galapagos islands became extinct within a decade after goats

Accepted Answer

According to the competitive exclusion principle, when two species compete for the same limited resources, the competitively superior species will eventually eliminate the other. The Abingdon tortoise in the Galapagos Islands became extinct within a decade after goats were introduced on the island. This occurred because the goats had a greater browsing efficiency compared to the tortoises, leading to a lack of food resources for the tortoises. Thus, Assertion A is correct, and Reason R is also c

Question 7

Which one of the following is an appropriate example of 'sexual deceit' ?

Accepted Answer

The Mediterranean orchid Ophrys employs 'sexual deceit' to get pollinated by a species of bee. One petal of its flower bears an uncanny resemblance to the female of the bee in size, colour, and markings. The male bee is attracted to what it perceives as a female, 'pseudocopulates' with the flower, and during that process is dusted with pollen from the flower. When this same bee 'pseudocopulates' with another flower, it transfers pollen to it and thus, pollinates the flower. Female wasp and fig e

Question 8

Who is known as the father of Ecology in India?

Accepted Answer

Ramdeo Misra is known as the father of Ecology in India.

Question 9

Given below are two statements : Statement I : Fig fruit is a non-vegetarian fruit as it has enclosed fig wasps in it. Statement II : Fig wasp and fig tree exhibit mutual relationship as fig wasp comp

Accepted Answer

Fig fruit is a vegetarian fruit as it only gets pollinated by wasp. Fig tree and fig wasps shows mutualism in which both species are benefitted. So, statement I is incorrect. Statement II is also not correct as fig inflorescence/flower gets pollinated by fig wasp.

Question 10

Which one of the following equations represents the Verhulst-Pearl Logistic Growth of population?

Accepted Answer

Logistic growth is described by Verhulst-Pearl logistic growth equation d N d t =r N ( K-N K ).

Question 11

Epiphytes that are growing on a mango branch is an example of which of the following?

Accepted Answer

Commensalism is the type of interaction in which one-species benefits and another is neither harmed nor benefited. An orchid growing as an epiphyte on a mango branch is an example of commensalism.

Organisms and Populations — Previous Year Questions & Solutions