Unit 5 Genetics Vocab

True-breeding

only one kind of trait

P generation

Parents

F1 generation

child/offspring

F2 generation

Child’s child

Alleles

Variation of a gene

Dominant Allele

Tends to be the functional protein

Recessive Allele

Tends to be the malfunctioning protein

Law of segregation

during mitosis alleles separate

homozygous

2 same alleles (BB)

heterozygous

2 different alleles (Bb)

Phenotype

physical description (shape/color)

Genotype

expression of genetic makeup (symbols or letters; Rr)

Test Cross

unknown dominant crossed with a recessive in order to try and figure out parents genotype

Law of independent assortment

homologous pairs do NOT influence eachother when lined up for metaphase 1

Incomplete dominance

Blend - heterozygote shows intermediate blended

Codominance

both - 2 alleles affect phenotype

Pleiotropy

one gene has many affects

epistasis

one gene completely masks another gene

Polygenic inheritance

some phenotypes are determined by additive effects of 2 or more genes on a single character ex: eye color

carrier

(Aa) may not display recessive trait but is heterozygous and can pass it on to offspring

Trait

a specific, observable characteristic or feature of an organism, determined by genes (genotype) and/or the environment

Wild type

most common naturally occuring phenotypes or genotypes (normal and nonmutated)

sex-linked genes

genes on sex chromosomes as opposed to autosomal chromosomes

linked genes

genes can be on some chromosome the further away the higher the cross over rate

nondisjunction

chromosomes dont separate properly (incorrect # of chromosomes)

trisomy

3 copies of chromosome

monosomy

1 copy of chromosome

deletion

delete a gene

duplication

replicate a gene

inversion

swap two genes

translocation

switched section with non homologous pairs (ABCDE HGI….HGCDE ABI)

Null hypothesis

a formal statement asserting that there is no statistically significant difference, relationship, or effect between variables

mutant phenotype

least common resulting from a permanent alteration in an organism's DNA (mutation)

Dihybrid cross

a genetic cross that examines the inheritance patterns of two different traits simultaneously between two organisms that are each heterozygous for both traits (BbYy x BbYy)

multiple alleles

occur when a gene exists in three or more distinct alleles forms within a population, rather than the standard two ex: blood types

Complete Dominance

In diploid (2n) organism the dominant allele can mask effects of recessive (Aa) A is shown

Aneuploidy

Wrong # of chromosomes

Polyploidy

an organism has more than two complete sets of chromosomes resulting from total nondisjunction during meiosis or mitosis

Barr body

inactive X chromosome found in the somatic cells of female mammals

Recombinants

organisms or gametes that possess new combinations of alleles or genetic material, differing from their parents (created from crossing over)

Parental Type

offspring that exhibit the exact same combination of traits as one of their parents

Genetic recombination

the process of rearranging genetic material, particularly by crossing over during meiosis, resulting in offspring with new, unique combinations of alleles that differ from either parent

Chromosome theory of inheritance

states that genes are located at specific positions (loci) on chromosomes and that the behavior of chromosomes during meiosis

hybrid

the offspring resulting from the mating or cross-breeding of two genetically distinct individuals

monohybrid cross

a genetic cross between two organisms that investigates the inheritance of a single characteristic or locus, often involving parents heterozygous for that trait