chp. 14 vocab

Question 1

allele

Answer 1

different versions of alleles which account for gene variation

Question 2

carrier

Answer 2

when a person has heterozygous alleles for a genetic disorder

Question 3

codominance

Answer 3

a situation where 2 alleles both affect the phenotype in separate, distinguishable ways

Question 4

complete dominance

Answer 4

a situation where 1 allele of a gene completely masks the affect of another allele

Question 5

cystic fibrosis

Answer 5

most common, lethal genetic disorder in U.S. where the membrane protein that helps in transport of chlorine ions btwn certain cells and the extracellular fluid; pleiotrophy, recessively inherited disorder

Question 6

dihybrid

Answer 6

individuals heterozygous for 2 characters (YYRr)

Question 7

dominant allele

Answer 7

if 2 alleles at a locus differ then the dominant allele determines organism’s appearance

Question 8

epistasis

Answer 8

a gene at one locus alters the phenotypic expression of a gene at a second locus

Question 9

F1 generation

Answer 9

the hybrid crossing of the parents (1st filial gen)

Question 10

F2 generation

Answer 10

the gen produced from the self-pollination of the F1 hybrids

Question 11

genotype

Answer 11

an organism’s genetic makeup (Pp)

Question 12

heterozygous

Answer 12

an organism that has 2 different alleles for that gene (Pp)

Question 13

homozygous

Answer 13

an organism with a pair of identical alleles for a character (PP, pp)

Question 14

Huntington’s disease

Answer 14

a dominantly inherited degenerative disorder in the nervous system where symptoms don’t show up until later in life

Question 15

hybridization

Answer 15

the mating/crossing of 2 true-breeding varieties

Question 16

dominance

Answer 16

the relationship between 2 versions of an allele where one is expressed over the other

Question 17

law of independent assortment

Answer 17

each pair of alleles segregates independently of each other during gamete formation

Question 18

law of segregation

Answer 18

the 2 alleles for a heritable character segregate during gamete formation and end up in different gametes

Question 19

monohybrid

Answer 19

heterozygous for 1 character (Rr)

Question 20

multifactorial

Answer 20

many factors, both genetic and environmental, collectively influence phenotype

Question 21

P generation

Answer 21

the true breeding generation (parental generation)

Question 22

pedigree

Answer 22

a family tree describing traits of parents and children across generations

Question 23

phenotype

Answer 23

an organism’s observable traits (purple flower)

Question 24

pleiotropy

Answer 24

the property where most genes have multiple phenotypic effects

Question 25

polygenic inheritance

Answer 25

a single gene affects 2 or more phenotypic characters

Question 26

punnett square

Answer 26

a way of predicting the allele composition of offspring from a cross between individuals of known genetic makeup

Question 27

recessive allele

Answer 27

compared to the dominant allele, the recessive with appear to have no affect

Question 28

sickle-cell allele

Answer 28

most common inherited disorder in people of African descent. Substitution of 1 amino acid in the hemoglobin protein of red blood cells; pleiotrophy

Question 29

Tay-Sachs disease

Answer 29

an inherited disorder in humans where the brain cells of a kid can't metabolize certain lipids because a crucial enzyme doesn't work

Question 30

test cross

Answer 30

breeding an organism of an unknown genotype with a recessive homozygote which reveals the unknown genotype

Question 31

trait

Answer 31

each variant for a heritable feature that varies among individuals (ex. flower color)

Question 32

true-breeding

Answer 32

generations of self-pollinating (for plants) that produces only the same variety as the parent plant