New Terms - Classical Genetics (by Mendel)

diploid cells - 		cells that have a double set of chromosomes, one from each parent
haploid cells - 	cells that have a single set of chromosomes
gametes - 		haploid cells or sex cells
genes - 		segments of DNA molecules that define a certain trait or characteristic
in organisms.
alleles - 		different forms of the same gene.  Remember that because of sexual
reproduction, the offspring receives one gene for each trait from each
parent.
homozygous - 	two identical alleles present for the same characteristic
heterozygous - 	two different alleles present for the same characteristic
dominant - 		when one allele is expressed (shown) over another; often expressed
with a capital letter (A).
recessive - 		the overshadowed allele; often expressed by a small letter (a).
genotype - 		all the genes present in an organism
phenotype - 		the observable traits in an organism, also known as gene expression
P - 			parental generation
F1 - 			first generation offspring
F2 - 			second generation offspring
homozygous dominant - individual has a pair of dominant alleles (AA)
heterozygous dominant - individual has one dominant and one recessive allele (Aa)
homozygous recessive - individual has a pair of recessive alleles (aa)
gene locus -		 the location of a gene on the chromosome; the plural is loci
law of dominance - 	when organism has two different alleles for the same trait, one allele
dominates.
law of segregation - 	diploid cells have pairs of genes, and during meiosis the two genes of
each pair separate and end up in different gametes.
law of independent assortment - gene pairs of homologous chromosomes are sorted into
one gamete or another independently of how gene pairs on other
chromosomes are sorted.
Punnett square - 	a boxed figure used to determine the probability of genotypes and
phenotypes in offspring.
incomplete dominance - when no single trait is dominant, but the allele combination blends.
multiple alleles - 	there are more than two alleles for a single trait; blood type is an
example
polygenic inheritance - when a trait is determined by the interaction of genes on several
chromosomes.
gene linkage - 	the transfer of a linkage group
linkage group - 	genes that are inherited together and are located on the same
chromosome
sex linkage - 		traits that are linked to sex chromosomes
sex chromosomes - 	chromosomes that determine the sex of an individual;  there are two
types - the X chromosome and the Y chromosome.  Females have two
X chromosomes and males have an X and a Y chromosome.
autosomes - 		all of the other chromosomes besides the sex chromosomes.  The other
22 pair in humans.