A mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring.
Animals that reproduce sexually produce sex cells, or gametes.
A mutation in the gametes of a parent can cause a new trait to appear in the parent 's offspring.
a mutation in the _ of a parent can cause a new trait to appear in the parent 's offspring

1: eggs
2: courtship
3: mitochondria
4: alleles
5: pollen
6: gametes
7: ATP
8: hormones