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Biology Ch 12.1
Ch.12 vocab
| Term | Definition |
|---|---|
| Sex chromosomes | contain genes that determine the sex of an individual |
| Autosome | any chromosome that is not a sex chromosome |
| Sex-linked trait | refers to a trait that is coded for by an allele on a sex chromosome |
| Linked gene | pairs of genes that tend to be inherited together |
| Chromosome map | a diagram of gene positions on a chromosome. shows the linear order of genes on a chromosome |
| MAP UNIT | frequency of crossing-over of 1 percent |
| Germ-cell mutation | occur in an organism's gametes. do not affect the organism itself, but they can be passed on to the offspring |
| Somatic-cell mutation | take place in an organism's body cells and can therefore affect the organism |
| LETHAL MUTATION | cause death, often before birth |
| Deletion | the loss of a part of DNA from a chromosome due to breakage |
| Inversion | a chromosomal segment breaks off, flips around backward, and reattaches |
| Translocation | a piece of one chromosome breaks off and reattaches to a nonhomologous chromosome |
| Nondisjunction | a chromosome fails to separate from its homologue during meiosis |
| Point mutation | is a change that occurs within a single gene or other segment of DNA on a chromosome |
| Substitution | one nucleotide replaces another |
| Frameshift mutation | making all amino acids downstream change |
| Insertion mutation | one or more nucleotides are added to a gene, which can also result in a frameshift mutation |