| A | B |
|---|
| gametes | sex cells |
| homozygous | both alleles are the same; either dominant or recessive |
| heterozygous | the two alleles are different; one is dominant and one is recessive |
| allele | a form of a gene; you have two copies |
| carrier | heterozygous female for X-linked characteristics |
| genotype | how the alleles are expressed; all the genetic combinations |
| phenotype | the observable genetic characteristics |
| monohybrid crosses | calculating the probability of one characteristic |
| Punnet square | tool for predicting genetic probability |
| dihybrid crosses | two pairs of alleles; Punnet square depicting more than one characteristic |
| spina bifida | a birth defect where there is incomplete closing of the backbone and membranes around the spinal cord. |
| sickle cell anemia | genetic disorder that impairs the body’s red blood cells |
| phenylketonuria (PKU) | metabolic disorder; individual cannot properly metabolize phenylalanine, an amino acid |
| Down Syndrome | genetic disorder caused by the presence of an extra copy of chromosome 21 |
| polygenic | characteristics determined by the interaction of many different genes |
