Living Environment Regents Practice Test

The genetic variability in Galapagos finches is primarily a result of which processes?

1. Crossbreeding and hybridization.

2. Meiosis and mutation.

3. Environmental adaptation alone.

4. Parasitism and competition.

The correct answer is: Meiosis and mutation.

The genetic variability in Galapagos finches is primarily a result of meiosis and mutation. Meiosis is the process of cell division that produces gametes (sperm and eggs) and introduces genetic diversity through independent assortment and crossing over. These mechanisms allow for a mix of alleles in offspring, contributing to variability in the population. Mutations are another crucial source of genetic variation, as they introduce new alleles into a gene pool. This can lead to new traits that may be beneficial for survival and reproduction in a specific environment, such as the diverse habitats found in the Galapagos Islands. While crossbreeding and hybridization can contribute to genetic variability, they are not as significant in the context of the finches on the Galapagos Islands, which have evolved distinct traits suited to their environments through natural selection processes. Environmental adaptation alone does not explain the mechanisms that generate genetic variation, and parasitism and competition relate more to ecological interactions than to the fundamental processes that create genetic diversity. Thus, meiosis and mutation are central to the genetic variability observed in these finches.