Evolution MCQs for NEET — Zoology Questions with Answers

Natural selection generally favors traits that provide some adaptive advantage. Traits that appear to have no adaptive value, as mentioned in option o4, are difficult to explain in terms of natural selection because they do not seem to offer any benefit for survival or reproduction.

A monophyletic taxon includes all the descendants of a common ancestor. The first fish species and every living organism that looks like a fish do not form a monophyletic group because it might exclude some descendants that do not look like a fish. In contrast, the first mammal species and all its descendants, as well as the first bird species and all its descendants, form monophyletic groups as they include all the descendants.

The correct answer is a combination of points 1 and 2. Organisms that look alike may be very distantly related to one another due to convergent evolution, where unrelated species independently evolve similar traits. Also, similarities between two species may be due to common descent without indicating how closely the two are related. This makes relying solely on similarity potentially misleading when inferring evolutionary relationships.

The correct answer is that some members of the ancestral population had larger beaks than others, and if larger beak size was advantageous, those individuals would be more likely to survive and reproduce. This explanation aligns with the concept of natural selection, where advantageous traits become more common in a population over time.

In an evolutionary sense, 'fitness' is defined by the ability to survive and reproduce. A lion who has many cubs, eight of which live to adulthood, has demonstrated higher fitness because it has successfully passed on its genes to a larger number of offspring who have also survived to reproduce.

To determine the ancestral state of a characteristic within a group of closely related species, it is useful to refer to an outgroup (a more distantly related species). By examining whether the outgroup has the characteristic in question (forked tongue in this case), the biologist can infer whether the characteristic is ancestral or derived. If the outgroup has the characteristic, it is more likely to be ancestral.

The Earth, like other planets, formed from a cloud of gas and dust known as the solar nebula. This process is part of the nebular hypothesis, which describes the formation of the solar system. The gravitational collapse of part of the nebula led to the formation of the Sun and the remaining material coalesced to form the planets.

The first formed organism, often referred to as a riboorganism, used RNA for catalyzing reactions. This is because RNA has the unique ability to both store genetic information and catalyze chemical reactions, a property not shared by DNA or proteins. This dual functionality of RNA supports the RNA world hypothesis, which suggests that self-replicating RNA molecules were precursors to current life forms.

The evolution of autotrophs, organisms that can produce their own food through processes like photosynthesis, required the evolution of chlorophyll. Chlorophyll is the pigment that allows these organisms to capture and convert light energy into chemical energy, setting the stage for autotrophic life forms.