| A | B |
|---|
| germ-cell mutation | a change in the DNA of a sex cell |
| lethal mutation | change in the DNA that causes death |
| sex-linked trait | a trait, associated with a gene that is carried by either the male or female parent (eg colorblindness) |
| sickle cell anemia | a genetic disorder caused by a point mutation that substitutes adenine for thymine in a single DNA codon |
| somatic mutation | a mutation that occurs in a body cell |
| x-linked gene | a gene found on the X chromosome |
| Y-linked gene | a gene found on the Y chromosome |
| 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 human genetic disorder caused by a dominant allele resulting in involuntary movements, mental deterioration, and eventual death |
| multiple allele trait | more than two forms of a gene controlling the expression of a trait |
| pattern of inheritance | repeated predictable patters of certain phenotypes from one generation to the next when analyzing pedigrees; single allele dominant/recessive, X-linked, polygenic and multiple alleles |
| pedigree | a diagram of the genetic history of an individual; can show how a trait is inherited over several generations |
| polygeneic trait | a trait in which the phenotype is controlled by two or more genes at different loci on different chromosomes (eg height) |
| single-allele trait | a trait controlled by a single allele |
| carriers | an individual who has one copy of a recessive autosomal allele who usually do not express the recessive allele, but can pass it along to their offspring |
