Question 1:

What is molecular evolution?

Explanation: Molecular evolution refers to the changes in DNA sequences and genetic information over time. It encompasses the study of genetic variation, mutations, and the processes that shape the evolution of genes and genomes. Therefore, option C is correct.

Question 2:

What is genetic drift?

Explanation: Genetic drift is the process of random changes in allele frequencies in a population over time. It occurs due to chance events and can lead to the loss or fixation of alleles in a population. Therefore, option A is correct.

Question 3:

Which of the following can increase the impact of genetic drift?

Explanation: Genetic drift is more pronounced in small population sizes. In smaller populations, chance events can have a greater impact on allele frequencies, leading to a higher degree of genetic drift. Therefore, option D is correct.

Question 4:

Which of the following is an example of genetic drift?

Explanation: The fixation of a harmful allele in a small population due to a chance event is an example of genetic drift. In this case, the allele becomes fixed in the population not because it provides any advantage, but due to random fluctuations in allele frequencies. Therefore, option C is correct.

Question 5:

How does molecular clock help in estimating evolutionary time scales?

Explanation: The molecular clock helps in estimating evolutionary time scales by analyzing the rate of genetic mutations in different species. By comparing the differences in DNA sequences between species, scientists can estimate the time since their last common ancestor. Therefore, option A is correct.