Question

It is believed that height of a child depends upon the genes inherited from parents. However, it is often seen that tall parents have short children and vice-versa. Find the reason.

Answer 1

Tall parents have short children because the traits are controlled by alleles of a particular gene. Alleles are variant forms of a gene present on homologous chromosomes and the parents are heterozygous for the height phenotype. Thus when the heterozygous parents mate they can give rise to pure tall, pure dwarf and heterozygous offsprings in the F1 generation. This is the reason because of which tall parents can also give rise to short children. However, short parents(intermediate height) can also give rise to tall offsprings because of these heterozygous alleles being randomly assorted into the progeny.