ch 9 vocab

Genetics

Genetics is the study of genes, genetic variation, and heredity in organisms

Heredity

he passing on of physical or mental characteristics genetically from one generation to another

True-breeding

A kind of breeding in which the parents with a particular phenotype produce offspring only with the same phenotype

Hybrid

the offspring of two plants or animals of different species or varieties

P generation

First Generation

F1 generation

second generation

F2 generation

third generation

Monohybrid cross

a genetic mix between two individuals with homozygous genotypes which result in an opposite phenotype

Dihybrid cross

A dihybrid cross describes a mating experiment between two organisms that are identically hybrid for two traits.

Allele

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome

Homozygous

same Gene (GG)

Heterozygous

different gene (Gg)

Dominant

a dominant trait or gene

Recessive

a trait that is expressed only when genotype is homozygous

Law of segregation

When gametes are formed, each allele of one parent segregates randomly into the gametes, such that half of the parent's gametes carry each allele

Punnett square

a square diagram that is composed of a grid of usually four boxes and is used to calculate and depict all the combinations

Phenotype

refers to an individual's observable traits

Genotype

the genetic makeup of an organism

Law of independent assortment

genes do not influence each other with regard to the sorting of alleles into gametes

Testcross

genetic cross between a homozygous recessive individual and a corresponding suspected heterozygote to determine the genotype