Evolution and natural selection: Practice Questions

Which of the following is considered the primary source of genetic variation in a population that reproduces asexually?

Which of the following best describes the role of random mutations in the process of evolution by natural selection?

The wings of a butterfly and the wings of a bat both serve the function of flight, yet their internal anatomical structures and embryonic origins are completely different. This is an example of:

According to the theory of natural selection, which of the following is the most important factor in determining whether a specific trait will be passed on to the next generation?

A population of insects lives in a forest with light-colored tree bark. Over several decades, industrial pollution stains the bark black. Scientists observe that the population of dark-colored insects increases while light-colored insects decrease. This is an example of:

Identify the term that describes the process where organisms with favorable traits are more likely to survive and reproduce in a specific environment.

In a population of flowering plants, a specific mutation occurs that allows for drought resistance. Explain how this genetic variation may lead to adaptation in the population over multiple generations if the environment becomes progressively drier.

In a population of soil bacteria, a rare spontaneous mutation occurs in the rpoB gene, which encodes the \(\beta\)-subunit of RNA polymerase, rendering the enzyme insensitive to the antibiotic rifampicin. Explain how the application of rifampicin acts as a selective agent to shift the population towards resistance and describe the role of vertical gene transfer in this process.

A species of finch lives on a remote island where seeds are the primary food source. Within this population, there is variation in the size and strength of beaks.

(a) State the primary source of new genetic variation in any population. (1 point)

(b) During a severe three-year drought, the only plants that survive produce large, hard-shelled seeds. Small, soft seeds become unavailable. Describe how natural selection will affect the beak size of the finch population over several generations. (2 points)

A species of lizard lives on an island where the main food source is insects hidden in narrow rock crevices. Within the population, there is genetic variation in head shape, ranging from wide to narrow heads.

(a) Explain how natural selection might lead to a change in the frequency of narrow-headed lizards over several generations if the crevices become narrower due to geological shifts.
(b) Describe the role of mutation in providing the raw material for this evolutionary process.