Question

In a case where two parents are heterozygous, why can't any pairs of their children be identical twins? As the question asks, I tried to explain this using the law of independent assortment, which states that alleles a gamete receives for one gene do not affect alleles for the other. I don't get how this relates to identical twins. When I searched this up, I found that identical twins come from when an egg splits into two, but if it's one cell, why would the law of independent assortment matter? Same with the heterozygous part - why would that affect the formation of identical twins when it's copies of the same cell? Any help is appreciated, thanks!

Answer 1

Mendel's law of independent assortment explains why it is not possible for pairs of children from heterozygous parents to be identical twins.

Step-by-step explanation:

Mendel's law of independent assortment states that genes do not influence each other with regard to the sorting of alleles into gametes, and every possible combination of alleles for every gene is equally likely to occur. This means that when two parents who are heterozygous for a specific gene have children, the alleles for that gene can assort independently into different gametes. Therefore, it is not possible for any pairs of their children to be identical twins because identical twins result from a single fertilized egg splitting into two separate embryos, which means they have the same genetic composition. In the case of heterozygous parents, each child would receive a different combination of alleles, resulting in different genetic compositions and preventing the development of identical twins