A mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring.
Alleles arise by mutation.
The sex cells of a parent can cause new alleles to appear.
What can cause new alleles to appear?
[a] skin cells
[b] coded genes
[c] sperm and egg fuse
[d] hair cells
[e] the parent's sex cells
[f] lung cells
[g] male gametes
[h] reproduction