Question

Assume for this calculation no recombinations or crossover . A male gamete (sperm) is haploid and has 23 chromosomes. These gametes can be selected from the father who has 2 pairs of 23 chromosomes each. So the total number of combinations for the male gamete is 2^23. The female gamete (ie the egg) which is again haploid has the same number of total combinations 2^23;

These chromosomes are selected from the mother who has 2 pairs with 23 chromosomes per pair. Thus the inital fertilized egg (ie one sperm plus one egg - ie diploid ) I believe this means should have (2^23)^2 possible chromosome combinations. Is this correct ?

Answer 1

In humans, there are over 8 million chromosome combinations in the production of gametes. Independent assortment and random fertilization contribute to the tremendous genetic variation between individuals. A sperm cell and an egg cell each have over 8 million chromosome combinations, resulting in over 64 trillion unique combinations when fertilized.

Step-by-step explanation:

In humans, there are over 8 million configurations in which the chromosomes can line up during metaphase I of meiosis. It is the specific processes of meiosis, resulting in four unique haploid cells, that result in these many combinations. This independent assortment, in which the chromosome inherited from either the father or mother can sort into any gamete, produces the potential for tremendous genetic variation. Together with random fertilization, more possibilities for genetic variation exist between any two people than the number of individuals alive today. Sexual reproduction is the random fertilization of a gamete from the female using a gamete from the male. In humans, over 8 million (2^23) chromosome combinations exist in the production of gametes in both the male and female. A sperm cell, with over 8 million chromosome combinations, fertilizes an egg cell, which also has over 8 million chromosome combinations. That is over 64 trillion unique combinations, not counting the unique combinations produced by crossing-over.