Why do cells hold chromosomes?

23. 1

24. Yes, and yes their shapes should be shaded.

Explanation:

23. In order to display a dominant trait, an individual only needs to have one copy of the dominant allele. This is in contrast to a recessive trait, where 2 copies of the allele are required in order to display the phenotype associated with the trait. The dominant allele will mask the display of the recessive allele

24. We are told the genotypes of the parents, which are both homozygous (hh and HH). This means that each child must inherit the h allele from their mother, as that is all she has to give, and the H from their father, as that is all he has to give.

That means all the children will have heterozygous Hh genotype. Because the widow's peak trait is dominant, that means they will have a widow's peak, and all 3 should be shaded.