Biology Regents Practice Exam

What is the primary function of meiosis in sexually reproducing organisms?

1. Production of identical somatic cells.

2. Generation of gametes with half the genetic material.

3. Restructuring of DNA for damage repair.

4. Facilitation of rapid cellular reproduction.

The correct answer is: Generation of gametes with half the genetic material.

The primary function of meiosis in sexually reproducing organisms is the generation of gametes, which are sex cells (sperm and eggs) that contain half the genetic material compared to somatic cells. This process is essential for sexual reproduction because it ensures that when two gametes fuse during fertilization, the resulting zygote has the correct diploid number of chromosomes. Meiosis involves two rounds of cell division, resulting in four non-identical daughter cells, each with half the chromosome number of the original cell. This reduction in chromosome number is crucial for maintaining the stability of an organism's chromosome count across generations. If gametes were produced through mitosis, which creates identical somatic cells, the chromosome number would double with each generation, leading to genetic chaos. In contrast, the other options focus on processes that do not align with the core purpose of meiosis. Identical somatic cell production is a function of mitosis, repairing DNA damage doesn't involve meiosis, and rapid cellular reproduction pertains more to mitotic processes rather than the specialized function of gamete formation. Thus, the generation of gametes with half the genetic material is what defines meiosis in the context of sexual reproduction.