Whether an allele is dominant or recessive depends on which of the following?

Question

whether it or another allele is expressed when they are both present,
how common the allele is relative to other alleles,
whether it is inherited from the mother or father,
which chromosome it is on

Answer 1

Actually, sometimes recessive alleles ARE expressed when paired with dominant alleles. This is the case in certain metabolic genes, in which both alleles are expressed. One allele may code for more production of an enzyme or protein, while the recessive allele codes for less production. In this case, alleles are said to be codominant. In early stages of human embryonic development, this is especially the case. However, in later years, when less enzyme is needed, the recessive allele may be "turned off."
The correct answer is still A - just thought you'd like some more insight on the question.

Answer 2

A. Whether it or another allele is expressed when both are present.

Answer 3

whether it or another allele is expressed when they are both present, because recessive allelles are never expressed when dominant alleles are present

Answer 4

His daughter. A man can donate an X or a Y. A woman can only donate an X. A woman has XX, and a man has XY. The only way a man can pass an X would be to a female, thus his daughter. Make sure you cite me.

Answer 5

A is the correct answer.