Fact 1: Amutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring.

Fact 2: Sometimes animal offspring look very different from their parents.

Given the two facts above, answer the question "A mutation in what of a parent can cause children to look very different from their parents?" with the following options: 
- chromosomes
 - sex cells
 - fur and fat
 - coded genes
 - hormones
 - sperm
 - epidermal
 - Enzymes


 

  sex cells       