Question

a gel contains two bands from a single str region on chromosome 5 for a heterozygous mother and two different bands for a heterozygous father. how many bands should be identical in size when comparing the heterozygous mother and her biological child? 0 1 2 4

Explanation:

Step1: Understand STR inheritance

A heterozygous individual has 2 distinct STR alleles. Offspring inherit 1 allele from each parent.

Step2: Determine child's allele from mother

The mother (heterozygous) passes 1 of her 2 alleles to the child. Thus, the child shares 1 identical STR band with the mother.

Answer:

1