A man who is aware that he is a silent carrier of the FMO3 ""fish odor syndrome"" gene has children with a woman who is ""normal."" Which statement would best explain how a child born from these parents could have fish odor syndrome?

This could be possible if the  wife  is a carrier of the FMO3 allele.   Therefore the two carrier parents must have  passed the defective alleles to the child, who now possessed the gene for the FMO3, and said to be dominant for the fish odor.

In genetics a Carrier  is an individual who inherited a defective allele (FMO3) , but do not show the manifestations of the allele, or symptoms of the diseases attributed to it. Therefore the wife is a Carrier for the allele if the child could show this symptoms of fish odor.

Explanation:

a- all cells come from pre-existing cells

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.