Vocabulary #1

allele	Alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome.
codominance	A condition in which both alleles of a gene pair in a heterozygote are fully expressed, with neither one being dominant or recessive to the other.
continuous variation dihybrid  cross	The outcome of the number of enviromental factors influencing the expression of traits in a population. experiment between P generation  organisms that differ in two traits.
epistasis	is when one gene hides the expression of another gene.
F1	The offspring of an initial genetic cross.
F2	The offspring of parents who are the first filial generation from a genetic cross.
gene	Unit of information for a heritable trait, passed from parents to offspring.
genotype	The combination of alleles located on homologous chromosomes that determines a specific characteristic or trait
heterozygous	refers to having two different alleles (one dominant and the other one recesive) for a single trait.
homozygous dominant	Having a pair of dominant alleles at a gene locus (on a pair of homologous chromosomes).           AA is homozygous dominant.                                                   Aa is heterozygous.                                                   aa is homozygous recesive.
homozygous recessive	Having a pair of recessive alleles at a gene locus (on a pair of homologous chromosomes).
hybrid offspring	Of a genetic cross, offspring having a pair of nonidentical alleles for a trait.
incomplete dominance	Condition in which one allele of a pair is not fully dominant.
independent assortment	traits are transmitted to offspring independently of one another.
monohybrid cross	experiment between P generation rganisms that differ in one trait.
multiple allele system	is when there are more than two possible allele pairs for a single locus.
phenotype	Observable trait or traits of an individual that arise from gene interactions and gene-environment interactions.
pleiotropy	The control of more than one phenotypic characteristic by a single gene or set of genes.
probability	The chance that each outcome of a given event will occur is proportional to the number of ways the outcome can be reached.
Punnett-square method segregation	Construction of a simple diagram as a way to predict probable outcomes of a genetic cross. states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization.
testcross	Experimental cross to determine whether an individual of unknown genotype that shows dominance for a trait is either homozygous dominant or heterozygous.
true-breeding lineage	a lineage in which only one version of a trait appears over the generations in all parents and their offspring