Biology Exam 1

Front 1

genetics

Back 1

the study of inheritance

Front 2

monohybrid cross

Back 2

a cross between true-breeding strains with alternative forms of a single trait

Front 3

reciprocal cross

Back 3

matings done with both genders, used to find sex-linked traits

Front 4

Principle of Uniformity in F1

Back 4

all offspring of true-breeding parents are alike and only resemble one parent

Front 5

particulate factors

Back 5

1. F1 resembled one parent but didn't breed true
2. F1 produced F2 offspring with traits that had disappeared in F1

Front 6

Principle of Segregation

Back 6

Each trait is controlled by particulate factors that occur in pairs. These factors segregate from each other during gamete formation so that each gamete receives one of each pair. The double number is restored upon fertilization

Front 7

locus

Back 7

the location of a gene on a chromosome

Front 8

test cross

Back 8

crossing an individual with a dominant phenotype with a pure-breeding recessive to find the individual's genotype

Front 9

Law of Independent Assortment

Back 9

pairs of alleles for genes on different chromosomes segregate independently during formation of gametes

Front 10

pleiotropy

Back 10

the creation of superficially unrelated effects by a single allele

Front 11

epistasis

Back 11

the masking of the effects of one gene by the allele of another

Front 12

1 out of 3

Back 12

the proportion of our genes required for viability

Front 13

penetrance

Back 13

the % of carriers of an allele that are somehow affected by that allele

Front 14

expressivity

Back 14

the extent to which a phenotype is altered in affected individuals

Front 15

germ cells

Back 15

give rise to sperm and eggs

Front 16

hemizygous

Back 16

a gene that's present in only one chromosome

Front 17

criss-cross inheritance

Back 17

gene transmission from the male P to the female F1 to the male F2

Front 18

dyads

Back 18

the chromosomes that separate during Anaphase I

Front 19

proband

Back 19

the affected individual through which a pedigree is discovered
male = propositus
female = proposita

Front 20

cis, coupling

Back 20

alleles that are together on the same homolog

Front 21

trans, repulsion

Back 21

alleles are together on different homologs