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 |