 | Term | Definition |
| |
inheritance |
the genetic transmission of characteristics from parents to offspring |
| |
alleles |
alternate forms of the same gene |
| |
homozygous |
both alleles the same for a gene |
| |
heterozygous |
both alleles different for a gene |
| |
hybrid |
the result of two inbreeding lines |
| |
self-fertilization |
the union of ones own egg with ones own sperm |
| |
true-breeding |
a plant line in which the offspring are homozygous and all have the same traits |
| |
cross-fertilization |
the union of egg and sperm from different parents |
| |
dominant |
an allele which when present is always expressed |
| |
recessive |
an allele that is only expressed when not in the presence of a dominant allele |
| |
genotype |
the organisms combination of cells |
| |
phenotype |
the organisms outward trait or appearance |
| |
punnent square |
used to determine the proportion of offspring produced from a cross |
| |
test cross |
breeding an individual with a homozygous recessive individual |
| |
law of independent assortment |
the independent inheritance of two or more traits |
| |
linkage |
genes on the same gene |
| |
genetic recombination |
the production of new allele combinations due to crossing over |
| |
sex chromosomes |
the chromosomes which determine sex |
| |
autosomes |
non-sex chromosomes |
| |
polygenetic inheritance |
two or more genes interact to express a phenotype |
| |
plieotrophy |
a single gene having multiple phenotypic effects |
| |
pedigree |
a diagram that shows the genetic relationship among related individuals |
| |
carrier |
a person who is phenotypicaly normal but carries a defective recessive allele |
| |
nondisjunction |
chromosomes not separating during meiosis |
| |
trisomy |
a genotypic condition of containing three copies of the same chromosome |
| |
p generation |
parental generation |
| |
f1 generation |
the first filial or first daughter generation |
| |
f2 generation |
the second filial or second daughter generation |
| |
multiple alleles |
the presence of more than two alternate alleles |
| |
epistasis |
one gene modifies the genotypic expression of another |
| |
continuous variation |
more than one gene contributes to the degree of expression of trait |
| |
incomplete dominance |
heterozygotes exhibiting exhibiting intermediate phenotypes |
