| A | B |
|---|
| deletion | a mutation where a piece of a chromosome is lost |
| frame-shift mutation | a change in the chromosome where the codons are incorrectly grouped |
| germ-cell mutation | a mutation that occurs in a cell that will eventually become a sperm or an egg, can be passed on to the offspring |
| inversion | a mutation where a chromosome is flipped |
| lethal mutation | a mutation that causes the individual to die |
| nondisjunction | when the homologous chromosomes fail to separate in meiosis |
| point mutation | the removal, addition, or substitution of a single nucleotide |
| sex-linkage | the presence of a gene on a sex chromosome |
| sickle cell anemia | a condition where the blood cells are shaped like sickles, can lead to impaired blood circulation and organ damage |
| somatic mutation | a mutation that happens in the body cells, it is not passed on the the offspring |
| substitution | a mutation where one nucleotide is substituted for another |
| translocation | a mutation where a piece of one chromosome breaks of and attaches to a different chromosome |
| X-linked gene | genes found on the X chromosome |
| Y-linked gene | genes found on the Y chromosome |
| amniocentesis | when a small amount of the amniotic fluid is removed to test for genetic diseases in the fetus |
| carrier | a person who carries the allele fro a disease but is not affected by it |
| chorionic villi sampling | a test where some of the tissue between the mother's uterus and the placenta is removed and tested for genetic disorders |
| colorblindness | a recessive X-linked trait where individuals cannot distinguish between certain colors |
| genetic counseling | informs individuals about the likelihood that their offspring will have a genetic disorder |
| genetic disorder | diseases or debilitating conditions that have a genetic basis |
| genetic marker | a short section of DNA that is known to have a close association with a particular gene located nearby |
| genetic screening | the examination of an individuals genetic makeup |
| hemophilia | a genetic disorder when the blood does not clot |
| monosomy | when an organism has only one chromosome in a homologous pair, usually results from nondisjunction |
| multiple-allele trait | a trait controlled by three or more alleles, like blood type in humans |
| pattern of inheritance | when certain phenotypes are repeated in in predictable patterns |
| pedigree | a family record that shows how a trait is inherited over several generations |
| polygenic trait | a trait that is controlled by two or more genes |
| sex-influenced traits | the presence of male or female hormones influences the expression of certain traits |
| single-allele trait | a trait that is controlled by a single dominant allele |
| trisomy | a condition when an organism has three copies of a chromosome, it usually occurs from nondisjunction |
