But the details are a bit more complex, because alleles influencing the antlers of offspring come from both parents, not just the bulls. Cows and bulls each carry the full complement of the elk genome. Genes important for antler growth may be silenced in cows (since cows do not grow antlers), but they will still be included in her eggs and passed to offspring. Thus, the antlers of sons will reflect the combination of alleles inherited from both parents.

Emlen, Douglas J, Animal Weapons_ The Evoluti…, loc. 882