what i learned from gcse double science.
het is a type of gene that can be either dominant or resessive. in organisms there is always two genes, one from the mother and one from the father.
if the mother is a normal (without hets), or double dominant, the genes she will carry are XX
if the father was a recessive, his genes would be xx.
all of the offspring would be het, having either Xx or xX genes.
if both paretns were hets, having Xx (or xX, there the same) the offspring would be 1/4 dominant XX, 1/4 recessive xx, and 1/4 recessive Xx (or xX).
it can easily be worked out in this table:
the mothers genes are in red, and the fathers in blue.
the diagram shows the likely outcome of the babies.
green is a het
mauve is the dominant
and yellow the ressesive.
if the one of the parents had differnt genes, the table would change acoordingly.
hope this helps.
Dan