Glossary of Terms:

albumen: the white of an egg
allele: an alternate form of a gene. Varients that occur at the same locus.
axial: Located on, around, or in the direction of an axis.
chromosome: a discrete structure composed of DNA (a double-stranded molecule that contains genetic code) and protein found only in the nuclei of cells.
dominant: a trait governed by an allele that can be expressed in the presence of another, different allele. Dominant alleles prevent the expression of recessive alleles in heterozygotes.
filial: having or assuming the relation of a child or offspring.
genotype: the genetic makeup of an individual; for a particular trait, you can't always tell the genotype by looking at the phenotype.
heterozygotes: organisms with heterozygous genes.
heterozygous: having different alleles at the same locus on a chromosome; a recessive and a dominant are paired (so the dominant trait is observed).
homozygous: having the same allele at the same locus on a chromosome; two recessive genes are paired, or two dominant genes are paired.
homozygous dominant: having dominant alleles at the same locus on a chromosome.
homozygous recessive: having recessive alleles at the same locus on a chromosome. This in the only time a recessive trait will be phenotypically (physically) seen.
hybrid: offspring of mixed ancestry.
locus: the portion of a chromosome responsible for the production of a polypeptide chain (a sequence of amino acids that may act alone (or in combination) as a functional protein).
Mendilian traits: traits that are under the influence of one genetic locus; also called simple traits (the trait is either one thing or another, there is no 'in between' mixing).
phenotype: the observable or detectable physical characteristics of an organism; the detectable expression of the genotype.
purebred: an organism who, when mated with another purebred with the same characteristics, will always produce purebreds; genotypically, purebreds are homozygous.
recessive: a trait that is not physically expressed in heterozygotes. In order for the trait to be expressed, there must be two copies of the allele.
terminal: growing at the end of a branch or stem.