chaper 15.1 and 16

Question 1

genetic variation

Answer 1

genetic differences that exist among individuals in a population at a particular time

Question 2

genotype

Answer 2

genetic makeup of a cell or organism

Question 3

polymorphism

Answer 3

refers to any genetic differences among individuals that is sufficiently common that it would almost certainly be present in a group of 50 randomly chosen individuals

Question 4

phenotype

Answer 4

an individual’s observable characteristics or traits

Question 5

alleles

Answer 5

different form of any gene

Question 6

homozygous

Answer 6

an individual that inherits an allele of the same type from each parent

Question 7

heterozygous

Answer 7

individuals who inherit different types of allele from each of their parents

Question 8

genotype-by-environment interaction

Answer 8

a phenotype is the result of an interplay between genes and the environment

Question 9

neutral mutation

Answer 9

have no effect on the organism, or have effects that are not associated with differences in survival or reproduction

Question 10

transmission genetics

Answer 10

the manner in which genetic differences among individuals are passed from generation to generation

Question 11

trait

Answer 11

characteristic of an individual

Question 12

blending inheritance

Answer 12

traits in the offspring resemble the average of those in the parents

Question 13

hybridization

Answer 13

interbreeding between two different varieties or species of an organism

Question 14

true breeding

Answer 14

the physical appearance of the offspring in each successive generation is identical to the previous one

Question 15

P1 generation

Answer 15

parental generation

Question 16

F1 generation

Answer 16

first offspring generation

Question 17

F2 generation

Answer 17

the offspring of the F1 generation

Question 18

reciprocal crosses

Answer 18

the expressions of the trait in the female and male parents are interchanged

Question 19

recessive

Answer 19

contrasting trait that does not appear

Question 20

dominant

Answer 20

the trait that does appear

Question 21

principle of independent assortment

Answer 21

the principle that segregation of one set of alleles of a gene pair is independent of the segregation of another set of alleles of a different gene pair

Question 22

Punnett square

Answer 22

a worksheet in the form of a checkerboard used to predict the consequences of a random union of gametes

Question 23

testcross

Answer 23

any cross of unknown genotype with a homozygous recessive genotype

Question 24

monohybrid cross

Answer 24

a genetic cross between homozygous individuals but with different alleles for a single gene locus of interest

Question 25

dihybrid cross

Answer 25

a breeding experiment between parental generation organisms that different in two traits

Question 26

incomplete dominance

Answer 26

the phenotype of the heterozygous genotype is intermediate between those of the homozygous genotypes

Question 27

principle of segregation

Answer 27

the principle by which half the gametes receive one allele of a gene and half receive the other allele

Question 28

probability

Answer 28

the likelihood that a specified genotype will occur

Question 29

addition rule

Answer 29

the principle that the probability of either of two mutually exclusive outcomes occurring is given by the sum of their individual probabilities

Question 30

multiplication rule

Answer 30

the principle that the probability of two independent events occurring together is the product of their respective probabilities

Question 31

linked genes

Answer 31

describes genes that are sufficiently close together in the same chromosome that they do not assort independently

Question 32

epistasis

Answer 32

genes the modify the phenotypic expression of other genes

Question 33

pedigree

Answer 33

a diagram of family history that summarized the record of the ancestral relationships among individuals

Question 34

incomplete penetrance

Answer 34

the individuals with a genotype corresponding to a trait do not actually show the phenotype due to the environment effects or interactions with other genes

Question 35

variable expressivity

Answer 35

a particular phenotype is expressed with a different degree of severity in different individuals