| A | B |
|---|
| pedigree | chart or family tree |
| multiple alleles | a single gene that has more than two alleles |
| environment | an organism's surroundings |
| sex-linked genes | genes on the X and Y chromosomes |
| males have only one of these type chromosomes | X chromosome |
| carrier | has one recessive allele and one dominant |
| widow's peak | an ordinary trait |
| single trait | when genes act together as a group to produce this |
| skin color | controlled by at least three genes |
| square | usually represents a male in a pedigree chart |
