Biology Regents Practice Exam

The variability in offspring of finches on the Galapagos Islands results from what processes?

1. Mutation and cloning

2. Meiosis and mutation

3. Mitosis and asexual reproduction

4. Mitosis and genetic recombination

The correct answer is: Meiosis and mutation

The variability in offspring of finches on the Galapagos Islands primarily results from meiosis and mutation. Meiosis is a type of cell division that occurs in the formation of gametes (sperm and eggs). It introduces genetic variation through processes such as independent assortment and crossing over, which shuffle alleles between homologous chromosomes. This genetic recombination leads to offspring that have combinations of traits different from those of their parents, contributing significantly to the diversity seen in the finch populations. Mutations are also vital in generating variability as they introduce new genetic variations into a population. These alterations in DNA can have various effects on the organisms, some of which may provide advantages in adapting to the specific environmental challenges present on the Galapagos Islands, like changes in food availability or habitat. Through the combined effects of meiosis and mutation, finch populations can develop unique characteristics that may help them to survive and thrive in their specific environments, which reflects the principles of evolution by natural selection.