Question
Question: How does genetics relate to meiosis?...
How does genetics relate to meiosis?
Solution
Meiosis is a type of cell division in organisms having sexual reproduction. Germ cells undergo reductional division to produce gametes. Crossing over occurs in meiosis which leads to new combinations.
Complete answer:
Gamete from each parent combines to form zygote after fertilization. Diploid germ cells of both the parents undergo 2 cycles of cell division and 1 cycle of DNA replication. In the end, 4 haploid gametes( 23 chromosomes ) are produced. At the end of meiosis in prophase, I phase of meiosis recombination or crossing over occurs. Homologous chromosomes pair and genetic material is exchanged between the chromosomes as chromosomes break and rejoin. This leads to unique combinations. This increases genetic diversity and also leads to evolution.
Additional information: Phases of meiosis are as follows
Prophase I: Chromosomes condense, nuclear membrane dissolves pairing of homologous chromosomes and recombination occur.
Metaphase I: Homologous chromosomes arrange at the equator
Anaphase I: Chromosomes separate and move to opposite poles
Telophase I: Reformation of the nuclear membrane and cell division occur leading to the formation of 2 daughter cells.
Prophase II DNA does not replicate again
Metaphase II: Each chromosome lines along the equator
Anaphase II: Separation of chromatids and move towards opposite poles.
Telophase II: Reappearance of nuclear membrane followed by cell division leading to the formation of 4 haploid daughter cells.
Note: In meiosis independent assortment and crossing over which is mainly responsible for genetic variations. Independent assortment occurs in the metaphase stage in which chromosomes from each parent align independently to each other. Also in crossing over genetic material is exchanged which leads to random variations Also, the random union of gametes during fertilization leads to variations.