One of the sources of genetic diversity in meiosis is independent assortment of chromosomes. What is independent assortment? A) The random lining up of homologous chromosomes double-file in the first part of meiosis
B) The pulling apart of the chromatids of replicated chromosomes to opposite sides of the cell near the end of meiosis
C) The orderly lining up of homologous chromosomes double-file in the first part of meiosis, so that all of mother’s chromosomes are in one column and all of father’s chromosomes are in a 2nd column
D) The intertwining and ‘trading pieces’ of homologous chromosomes in the first part of meiosis
The correct answer and explanation is:
The correct answer is A) The random lining up of homologous chromosomes double-file in the first part of meiosis.
Explanation:
Independent assortment is a fundamental concept in genetics, describing the process that occurs during meiosis I, specifically during metaphase I. During this stage, homologous chromosomes (one set from the mother and one set from the father) line up in pairs along the equator of the cell. The crucial aspect of independent assortment is that the orientation of these chromosome pairs is random. This means that the maternal and paternal chromosomes do not align in any specific pattern. As a result, when the chromosomes are later separated into different cells, the combination of chromosomes that end up in each gamete (egg or sperm) is unique.
This random arrangement of chromosomes during meiosis contributes to genetic diversity in offspring because it allows for the mixing of genetic material from both parents. The number of possible combinations of chromosomes that can be produced by independent assortment depends on the number of chromosome pairs in the species. For humans, with 23 pairs of chromosomes, the number of different combinations of chromosomes that can be passed on to offspring is approximately 8.4 million (2^23). This creates a vast array of potential genetic combinations.
Independent assortment is just one of the processes that increases genetic diversity. It works in conjunction with other mechanisms, such as crossing over (the exchange of genetic material between homologous chromosomes during meiosis I), which further reshuffles the genetic material. The overall result is a wide variation in the genetic makeup of offspring, even though they inherit half of their genetic material from each parent. This genetic diversity is important for evolution, adaptation, and the survival of populations.