Ch 14

Question 1

character

Answer 1

heritable feature

Question 2

trait

Answer 2

variant for each character

Question 3

true-breeding

Answer 3

only produced same variety over many generations of self-pollination

Question 4

hybridization

Answer 4

crossing of two true-breeding varieties

Question 5

P generation

Answer 5

parental, the true-breeding parents

Question 6

F1 generation

Answer 6

first filial, hybrid offspring

Question 7

F2 generation

Answer 7

second filial, produced by F1

Question 8

alleles

Answer 8

alternative versions of genes

Question 9

Alleles account for what in inherited characters?

Answer 9

variation

Question 10

An organism inherits # copies of a gene…

Answer 10

two, one from each parent

Question 11

If the two alleles differ…

Answer 11

Dominant determines the appearance; recessive has no noticeable effect

Question 12

Mendel’s Principles

Answer 12

1. Law of Dominance
2. Law of Segregation
3. Law of Independent Assortment

Question 13

Law of Dominance

Answer 13

In a heterozygote, the allele expressed is the dominant allele

Question 14

Law of Segregation

Answer 14

two alleles for a heritable character segregate, separate from each each other, during gamete formation and end up in different gametes

Question 15

Law of Independent Assortment

Answer 15

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

Question 16

homozygous

Answer 16

pair of identical alleles

Question 17

heterozygous

Answer 17

two different alleles

Question 18

phenotype

Answer 18

appearance or observable traits

Question 19

genotype

Answer 19

genetic makeup

Question 20

testcross

Answer 20

breeding to reveal an unknown genotype

Question 21

monohybrid

Answer 21

heterozygous for a particular character

Question 22

dihybrid

Answer 22

heterozygous for two characters

Question 23

Expected ratio of a dihybrid cross

Answer 23

9:3:3:1

Question 24

What does 9:3:3:1 mean?

Answer 24

9 double dominant, 3 one dominant one recessive, 3 swapped, 1 double recessive

Question 25

What are the monohybrid ratios?

Answer 25

3:1 phenotype and 1:2:1 genotype

Question 26

complete dominance

Answer 26

phenotypes of heterozygous and homozygous dominant are identical

Question 27

incomplete dominance

Answer 27

heterozygotes have a third intermediate phenotype

Question 28

codominace

Answer 28

both alleles are distinguishable in phenotype

Question 29

Pleiotropy

Answer 29

when genes have multiple phenotypic effects

Question 30

epistasis

Answer 30

phenotypic expression of one gene alters that of another gene at another locus

Question 31

In labs, the gene for ________ is ________ to the coat color

Answer 31

pigment deposition

epistatic

Question 32

Epistasis ratio

Answer 32

9:3:4

Question 33

quantitative characters

Answer 33

vary along a continuum

Question 34

polygenic inheritance

Answer 34

two or more genes affect a single phenotypic character like skin color

Question 35

multifactorial

Answer 35

many factors, both genetic and environmental, collectively influence phenotype

Question 36

norm of reaction

Answer 36

phenotypic range for genotype

Question 37

pedigree

Answer 37

family tree of a trait

Question 38

pedigree rules

Answer 38

square is male
circle is female
affected shaded in
offspring in birth order

Question 39

carrier

Answer 39

heterozygote for disease

Question 40

sickle-cell disease: beneficial or deleterious?

Answer 40

B: protects against malaria
D: clogs blood vessels