In humans, freckles are dominant to no freckles. A man with
freckles is married to a woman with freckles, but the
children have no freckles. What's the reason?
Answer Posted / danny
Freckles are a known dominant trait in humans. However,
this does not mean that the parents with freckles don't have
the gene for no freckles. If Both parents had a child with
no freckles this means that they do have that gene, but the
dominant freckle gene is active. They both have two genes
for freckles, but their gene for no freckles is recessive.
This is like math, A=freckles, a=no freckles
Mom=Aa
Dad=Aa
When the sex chromosomes split in the sperm/ova, unlike in
all other cells, they don't carry both genes with them only
one. This means that when the sperm and ova meet, there is
a chance that the A meets with A, or A with a, or a with A,
or a with a, which would mean there is a one in 4 chance
that the child will have no freckles.
Aa, aA, AA, aa
| Is This Answer Correct ? | 16 Yes | 1 No |
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