mendelian genetics vocab

true breeding

organisms that exhibit the same traits, generation after generation

P generation

in breeding, the organisms initially crossed and are typically true breeding

F1 generation

the offspring of a cross of the P generation

F2 generation

the offspring of a cross between the F1 generation

Monohybrid cross

a cross of two individuals that differ by one trait

Law of Segregation

traits are determined by pairs of alleles that segregate during meiosis so that each gamete receives one allele

Dominant

the form of a trait that always appears when an individual has an allele for it

Recessive

the form of a trait that always appears when an individual has two alleles for it

Genotype

the combination of alleles for any given trait, or the organisms entire genetic makeup

Phenotype

the physical and physiological traits of an organism

Homozygous

an organism that has two identical alleles for a gene ex. TT

Heterozygous

an individual that has two different alleles of a gene ex. Tt

punnett square

a grid used to illustrate all possible genotypes and phenotypes of offspring from genetic crosses

test cross

a cross between a parent of an unknown genotype and a homozygous recessive parent

dihybrid cross

a cross of two individuals that differ in two traits due to two different genes

law of independent assortment

during gamete formation, the two alleles for one gene segregate or assort independently of the alleles for other genes

chromosome theory of inheritance

traits determined by genes are inherited through the movement of chromosomes during meiosis

pedigree

a flowchart that uses symbols to show the inheritance patterns of traits in a family over many generations

autosomal dominant disorder

the inheritance of a dominant phenotype whose gene is on an autosomal chromosome

autosomal recessive

the inheritance of a recessive phenotype whose gene is on an autosomal chromosome