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Advanced Biology 15
Term | Definition |
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Chromosome Theory of Inheritance | A basic principle in biology stating that genes are located at specific positions (loci) on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns. |
Wild Type | The phenotype most commonly observed in natural populations; also refers to the individual with that phenotype. |
Sex-Linked Gene | A gene located on either sex chromosome. |
Barr Body | A dense object lying along the inside of the nuclear envelope in cells of female mammals, representing a highly condensed, inactivated X chromosome. |
Linked Genes | Genes located near each other on the same chromosome which tend to be inherited together. |
Genetic Recombination | General term for the production of offspring with combinations of traits that differ from those found in either parent. |
Crossing Over | The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis. |
Genetic Map | An ordered list of genetic loci (genes or other genetic markers) along a chromosome. |
Nondisjunction | An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other. |
Mutation | A change in the nucleotide sequence of an organism’s DNA or in the DNA or RNA of a virus. |
Aneuploidy | A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number. |
Polyploidy | A chromosomal alteration in which the organism possesses more than two complete chromosome sets. It is the result of an accident of cell division. |
Deletion | (1) A deficiency in a chromosome resulting from the loss of a fragment through breakage. |