| A | B |
|---|
| germ-cell mutation | a mutation that occurs in an organism's gametes |
| lethal mutation | a gene or chromosomal mutation that influences the development of an organism in such a way that the organism cannot survive |
| sex-linked trait | a trait that is determined by a gene found on one of the sex chromosomes, such as the X or Y chromosome in humans |
| sickle cell anemia | a genetic disorder caused by a point mutation that substitutes adenine for thymine in a single DNA codon |
| somatic cell mutation | a mutation that occurs in a body cell |
| linked gene | one of a pair of genes that tend to be inherited together |
| colorblindness | a recessive X-linked disorder in which an individual cannot distinguish between certain colors |
| Duchenne muscular dystrophy | a form of muscular dystrophy that weakens and progressively destroys muscle tissue |
| hemophilia | a trait in which the blood lacks a protein that is essential for clotting |
| Huntington's disease | a rare hereditary disease of the brain characterized by involuntary movements of the limbs or face, decreasing mental abilities and eventual death |
| multiple allele | more than two alleles (version of a gene) for a genetic trait |
| pattern of inheritance | repeated predictable patterns of certain phenotypes from one generation tot he next when analyzing pedigrees; single allele dominant/recessive, X-linked, polygenic and multiple alleles |
| pedigree | a diagram that shows the occurrence of a genetic trait in several generations of a family |
| polygenic trait | describes a characteristic that is influenced by many genes |
| single-allele trait | a trait controlled by a single gene |
| carrier | in genetics, an individual who has one copy of a recessive autosomal allele that carries disease in homozygous condition |
