Chapter 12

Question 1

a specific heritable attribute or property of an organism

Answer 1

character

Question 2

one of the forms of a genetic character

Answer 2

traits

Question 3

alternative forms of characters

Answer 3

character differences

Question 4

fertilization in which sperm nuclei in pollen fertilize egg cells of the same

Answer 4

self-fertilization

Question 5

fertilization of one plant by a different plant

Answer 5

cross-fertilization/cross-pollination

Question 6

individual that passes traits without change from one generation to the next

Answer 6

true-breeding

Question 7

a genetic cross in which the 2 parents are switched with respect to which trait is associated with each sex

Answer 7

reciprocal cross

Question 8

the parental individuals used in an initial genetic cross

Answer 8

P generation

Question 9

first generation of offspring from a genetic cross

Answer 9

F1 generation

Question 10

second generation of offspring from a genetic cross produced by interbreeding F1 individual

Answer 10

F2 generation

Question 11

one of 2 or more versions of a gene

Answer 11

alleles

Question 12

the masking effect of one allele over another

Answer 12

dominance

Question 13

mendel’s principle that the pairs of alleles that control a character segregate as gametes are formed with half the gametes carrying one allele, and the other half carrying the other allele

Answer 13

principle of segregation

Question 14

an individual with 2 copies of same allele

Answer 14

homozygote

Question 15

state of possessing 2 copies of the same allele

Answer 15

homozygous

Question 16

an individual with 2 different alleles of a gene

Answer 16

heterozygote

Question 17

state of possessing 2 different alleles of a gene

Answer 17

heterozygous

Question 18

an F1 heterozygote produced from a genetic cross involves a single character

Answer 18

monohybrid

Question 19

a genetic cross between 2 individuals that are each heterozygous for the same pair of alleles

Answer 19

monohybrid cross

Question 20

the genetic constitution of an organism in terms of its genes and alleles

Answer 20

genotype

Question 21

the observable or measurable characteristics of an organism that are produced by an interaction between the genotype and the environment

Answer 21

phenotype

Question 22

the possibility that an outcome will occur if it is a mater of chance

Answer 22

probability

Question 23

mathematical rule in which the final probability is found by multiplying individual probabilities

Answer 23

product rule

Question 24

mathematical rule in which final probability by summing individual probabilities

Answer 24

sum rule

Question 25

method for determining the genotype and phenotype of offspring and their expected proportions by combining gametes and their probabilities of occurrence in a matrix table

Answer 25

punnett square

Question 26

a genetic cross between an individual with the dominant phenotype and a homozygous recessive individual

Answer 26

testcross

Question 27

a zygote produced from a cross that involves 2 characters

Answer 27

dihybrid

Question 28

a cross between 2 individuals that are heterozygous for 2 pairs of alleles

Answer 28

dihybrid cross

Question 29

Mendel's principle that the alleles of the genes that govern 2 characters assort independently during formation of gametes. mechanistically this is the case because any combination of chromosomes may be segregated to the spindle poles during meiosis I

Answer 29

independent assortment

Question 30

Mendel's principle that the alleles of the genes that govern 2 characters assort independently during formation of gametes

Answer 30

Principle of Independent Assortment

Question 31

the principle that genes and their alleles are carried on the chromosomes

Answer 31

chromosome theory of inheritance

Question 32

the particular site on a chromosome at which a gene is located

Answer 32

locus

Question 33

condition in which the effects of recessive alleles can be detected to some extent in heterozygotes

Answer 33

incomplete dominance

Question 34

condition in which alleles have approximately equal effects in individuals making the alleles equally detectable in heterozygotes

Answer 34

codominance

Question 35

more than 2 different alleles of a gene

Answer 35

multiple alleles

Question 36

interaction of genes with one or more alleles of a gene at one locus inhibiting or masking the effects of one or more alleles of a gene at a different locus

Answer 36

epistasis

Question 37

inheritance in which several to many different genes contribute to the same character

Answer 37

polygenic inheritance

Question 38

a character that displays a continuous distribution of the phenotype involved typically resulting from several to many contributing genes

Answer 38

quantitative traits

Question 39

the individual genes that contribute to a quantitative trait

Answer 39

quantitative trait loci

Question 40

condition in which single genes affect more than one character of an organism

Answer 40

pleitropy

Question 41

theory suggesting that hereditary traits blend evenly in offspring through mixing of the blood of 2 parents

Answer 41

blending theory of inheritance