Chapter 13 Vocabulary

aneuploid

individual with an error in chromosome number; includes chromosome segment deletions and duplications

autosome

any of the non-sex chromosomes

centimorgan (cM)

(also, map unit) relative distance that corresponds to a 0,01 recombination frequency

Chromosomal Theory of Inheritance

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

chromosome inversion

detachment, 180° rotation, and chromosome arm reinsertion

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 crossing over

karyogram

a karyotype's photographic image

karyotype

an individual's chromosome number and appearance; 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 meiosis' first cell division

nonparental (recombinant) type

progeny resulting from homologous recombination that exhibits a different allele combination compared with its parents

paracentric

inversion that occurs outside 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 progeny's population

translocation

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

trisomy

otherwise diploid genotype in which one entire chromosome duplicates

X inactivation

condensing X chromosomes into Barr bodies during embryonic development in females to compensate for the double genetic dose