Explain the role of meiosis in sexual reproduction and
genetic variation.
genetic variation.
If sexual reproduction was a movie, Meiosis would be the star. Meiosis is what allows sexual reproduction to involve genetic variation. As mitosis produces regular cells with 46 chromosomes each, Meiosis produces sex cells with only 23 chromosomes each. This allows both the man and the woman to contribute to the child's traits, in that the child receives half of its chromosomes from each parent.
"To illustrate this concept, consider the variety derived from just three hypothetical chromosome pairs, as shown in the following example (Hirsch, 1963). Each pair consists of two homologues: one maternal and one paternal. Here, capital letters represent the maternal chromosome, and lowercase letters represent the paternal chromosome:
- Pair 1: A and a
- Pair 2: B and b
- Pair 3: C and c
When these chromosome pairs are reshuffled through independent assortment, they can produce eight possible combinations in the resulting gametes:Miko Ph. D., Illona. "Mitosis, Meiosis, and Inheritance." Nature.com. Nature Publishing Group, 1 Jan. 2008. Web. 28 Apr. 2014. <http://www.nature.com/scitable/topicpage/mitosis-meiosis-and-inheritance-476>.
- A B C
- A B c
- A b c
- A b C
- a B C
- a B c
- a b C
- a b c "