CSIR NET 2022 | Life Science : (Evolution and Behaviour) | (22 January) for CSIR NET & SET Exams

Question 1

Which of the following best describes Darwin's theory of evolution?

Question 2

Which of the following is true of cladogenesis?

Question 3

Pink salmon (Onchorhynchus gorbuscha) in the Pacific Northwest have been decreasing in size in recent years. In 1945, fishermen started being paid by the pound, rather than per individual, for the salmon they caught, and they increased the use of gill netting, which selectively takes larger fish. The selectivity of gill netting can be shown by comparing the average size of salmon taken by gill netting with those taken by an unselective fishing technique: the difference ranged from 0.14-0.22 kg. Therefore, after gill netting was introduced, smaller salmon had a higher chance of survival. The selection favoring small size in the salmon population was intense, because fishing effort is highly efficient a about 75-80% of the adult salmon swimming up the rivers under investigation were caught in these years. The average weight of salmon duly decreased, by about one-third, in the next 25 years. This is an example in favour of:

Question 4

While studying the frogs of a certain species in their natural habitat during the mating season, you observe a chorus of male frogs in which some individuals are calling while others remain silent. On further observation, you see the silent frogs are sitting closer to those that are calling.
Which of the following is most likely to explain the behaviour of this chorus of frogs?

Question 5

Prey-predator relationships are often considered analogous to a "life-dinner" relationship in behavioural ecology.
I. This analogy indicates the fact that the prey species serves as the "dinner" for the predator species, the "life" of which depends on the former.
II. This analogy indicates that a prey species caught by a predator loses its "life" while a predator that fails to catch a prey only loses a "dinner".
III. The prey species is usually under greater selection pressure from its predators and tends to evolve faster than does a predator species.
IV. The predator species is usually under greater selection pressure because of its dependence on a prey species for food and tends to evolve faster than does a prey species.

Which of the following statements best describe this analogy and the relative evolutionary rates of the prey and predator species in a population?