Download TRAIT

GENETICS VOCABULARY
TRAIT – a characteristic of something, for example, eye color
GENE – a distinct unit of hereditary material found in chromosomes
ALLELE – different forms of the same gene
DOMINANT – the allele of a gene that is expressed when both alleles present are not the same
RECESSIVE – the allele of a gene that is not expressed when both are not the same
HOMOZYGOUS – pure-bred; when both alleles for a trait are the same (r,r)
PURE-BRED – when both genes of a trait in an individual have the same allele (R,R)
HETEROZYGOUS – hybrid; when both alleles for a trait are different (P,p)
HYBRID – when both genes of a trait in an individual have different alleles (N,n)
GENOTYPE – what alleles an individual has for a trait, always represented by two letters (G,g)
PHENOTYPE – how genes are expressed; what the individual looks like
SEX CHROMOSOMES – chromosomes that determine the sex (gender) of an individual
AUTOSOMES – all chromosomes that are not sex chromosomes
LINKED GENES – genes on the same chromosome
SEX-LINKED GENE – a gene on one of the sex chromosomes
SEX-LINKED TRAIT – a trait controlled by a gene on one of the sex chromosomes
CROSSING OVER – during prophase I of meiosis sister chromatids overlap and swap genes
MUTATION – a sudden change in the genetic material, DNA
NONDISJUNCTION – when chromosomes fail to separate during cell division resulting
in too many or too few chromosomes in the daughter cells
GENETIC RECOMBINATION – the formation of new combinations of alleles