More help please?

Question

Explain how the parents of an individual who expresses a recessive gene can both not express the gene?

Answer 1

I think what your getting at here is how recessive gene overlooks a dominant one. In this situation the child would have 2 recessive genes whilst the parents would have a recessive gene but also a dominant one of the same form - the dominant one takes centre stage so the phenotypical effects of the recessive one is not expressed unlike the childs recessive gene expression.

Hope this helps.

Answer 2

The parents would be heterozygous, having both the dominant gene and the recessive gene. The child has a 1/4 chance of being homozygous in relation to the recessive gene.

Example:

Parents      Aa  x  Aa

Gametes   A   a      A    a

Offspring   AA  Aa  Aa aa

The "aa here being the child who expresses the recessive gene. The rest of the children will not express it, although two children will be carriers of the