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Biology for AP® Courses

Key Terms

Biology for AP® CoursesKey Terms

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aneuploid: individual with an error in chromosome number; includes deletions and duplications of chromosome segments

autosome: any of the non-sex chromosomes

centimorgan (cM): (also, map unit) relative distance that corresponds to a recombination frequency of 0.01

Chromosomal Theory of Inheritance: theory proposing that chromosomes are the vehicles of genes and that their behavior during meiosis is the physical basis of the inheritance patterns that Mendel observed

chromosome inversion: detachment, 180° rotation, and reinsertion of a chromosome arm

euploid: individual with the appropriate number of chromosomes for their species

homologous recombination: process by which homologous chromosomes undergo reciprocal physical exchanges at their arms, also known as crossing over

karyogram: photographic image of a karyotype

karyotype: number and appearance of an individuals chromosomes; includes the size, banding patterns, and centromere position

monosomy: otherwise diploid genotype in which one chromosome is missing

nondisjunction: failure of synapsed homologs to completely separate and migrate to separate poles during the first cell division of meiosis

nonparental (recombinant) type: progeny resulting from homologous recombination that exhibits a different allele combination compared with its parents

paracentric: inversion that occurs outside of the centromere

parental types: progeny that exhibits the same allelic combination as its parents

pericentric: inversion that involves the centromere

polyploid: individual with an incorrect number of chromosome sets

recombination frequency: average number of crossovers between two alleles; observed as the number of nonparental types in a population of progeny

translocation: process by which one segment of a chromosome dissociates and reattaches to a different, nonhomologous chromosome

trisomy: otherwise diploid genotype in which one entire chromosome is duplicated

X inactivation: condensation of X chromosomes into Barr bodies during embryonic development in females to compensate for the double genetic dose

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- Authors: Julianne Zedalis, John Eggebrecht
- Publisher/website: OpenStax
- Book title: Biology for AP® Courses
- Publication date: Mar 8, 2018
- Location: Houston, Texas
- Book URL: https://openstax.org/books/biology-ap-courses/pages/1-introduction
- Section URL: https://openstax.org/books/biology-ap-courses/pages/13-key-terms

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