Chapter 12, Patterns of Inheritance

Question 1

Before the 20th century, what were the two concepts that were the basis for ideas about heredity?

Answer 1

1. Heredity occurs within species
2. Traits are transmitted directly from parent to offspring

Question 2

___________-1760- crossed tobacco strains to produce hybrids

Answer 2

Josef Kolreuter

Question 3

What two observations did Josef Kolreuter make about the hybrids?

Answer 3

1. hybrid offspring differed from both parents
2. additional variation observed in 2nd generation offspring contradicts direct transmission

Question 4

__________ -1823- crossed two varieties of garden pea, Pisum sativa

Answer 4

T.A Knight

Question 5

T.A knight crossed two _____-______ strains

Answer 5

true-breeding

Question 6

What does it mean if a species is true-breeding?

Answer 6

with self-fertilization it produces one type

Question 7

In T.A knight’s experiment’s 1st generation resembled only 1 ______ strain

Answer 7

parent

Question 8

In T.A Knight’s experiment’s the 2nd generation resembled ______ strains

Answer 8

both parent

Question 9

Why did Gregor Mendel use pea plants?

Answer 9

1. other research showed that pea bybrids could be produced
2. many pea varieties were available
3. peas are small plants an easy to grow
4. Peas can self-fertilize or be cross-fertilized

Question 10

What was Mendel’s experimental method?

Answer 10

1. Produce true-breeding strains for each trait he was studying
2. cross-fertilize true-breeding strains having alternate forms of a trait
3. Allow the hybrid offspring to self-fertilize for several generations and count the number of offspring showing each form of the trait

Question 11

How did Mendel conduct his experiments?

Answer 11

1. The anthers are cut away on the purple flower
2. pollen is obtained from the white flower
3. Pollen is transferred to the purple flower
4. All progeny result in purple flowers

Question 12

________ cross used to study only two variations of single trait

Answer 12

monohybrid

Question 13

Mendel produced true-breeding pea strains for _____ different traits

Answer 13

seven

Question 14

What are the seven traits of plants?

Answer 14

flower color, seed color, seed texture, pod color, pod shape, flower position, plant height, plant

Question 15

F1 generation is also called ____________

Answer 15

first filial generation

Question 16

For every trait Mendel studied, all F1 plants resembled the same _____

Answer 16

parent

Question 17

The visible trait is referred to as _____

Answer 17

dominant

Question 18

In Mendel’s experiments, no ________ inheritance was found

Answer 18

blending

Question 19

F2 is the second ______ generation

Answer 19

filial

Question 20

_____ ______ generation was produced from the self-fertilization of F1 plants

Answer 20

second filial

Question 21

What is the F2 phenotypic ratio?

Answer 21

3:1

Question 22

What is the genotypic ratio of F2 generation?

Answer 22

1 true-breeding dominant
2 not-true breeding dominant plants
1 true-breeeding recessive plant

Question 23

What is Mendel’s five-element model?

Answer 23

1. parents transmit discrete factors (genes)
2. each individual receives one copy of a gene from each parent
3. Not all copies of a gene are identical
4. alleles remain discrete-no blending
5. presence of allele does not guarantee expression

Question 24

_____ is an alternatve form of a gene

Answer 24

allele

Question 25

_______- two of the same allele

Answer 25

homozygous

Question 26

________-different alleles

Answer 26

heterozygous

Question 27

What is the principle that two alleles for a gene segregate during gamete formation and are rejoined at random during fertilization?

Answer 27

principle of segregation

Question 28

The physical basis for allele segregation is the movement of ______ during meiosis

Answer 28

chromosomes

Question 29

In Punnett squares the top right section contains the _____ DNA

Answer 29

male's

Question 30

In the punnett square the side left contains the _____ DNA

Answer 30

female's

Question 31

Each true-breeding parent makes only one type of ______

Answer 31

gamete

Question 32

________ cross used to study two variations of two traits in a single cross

Answer 32

Dihbrid

Question 33

In the F2 dihybrid cross what is the phenotypic ration produced?

Answer 33

9:3:3:1

Question 34

In a dihybrid cross, the alleles of each gene assort ________

Answer 34

independently

Question 35

The segregation of different allele pairs is ______

Answer 35

independent

Question 36

Independent alignment of different homologous chromosomes pairs during _______ I leads to the independent segregation of the different allele pairs

Answer 36

metaphase

Question 37

______ is used to determine the genotype of an individual with unknown phenotype

Answer 37

testcross

Question 38

In a testcross the unknown genotype is crossed with a homozygous _____

Answer 38

recessive

Question 39

______ allows the prediction of liklihoods of random events

Answer 39

probability

Question 40

Rule of ______ is the probability of either of two mutually exclusive events occurring is the sum of their individual probabilities

Answer 40

addition

Question 41

rule of ________ is the probability two independent events both occurring is the product of their individual probabilities

Answer 41

multiplication

Question 42

_____ probabilities are based on monohybrid probabilities

Answer 42

dihybrid

Question 43

Principle of _______ _____ means one dihybrid cross is equivalent to two independent monohybridcrosses

Answer 43

independent assortment

Question 44

What does Mendel's model of inheritance assume?

Answer 44

1. Each trait is controlled by a single gene 2. each gene has only two alleles 3. there is a clear dominant-recessive relationship between the alleles

Question 45

______ _____ is where more than one gene can affect a single trait

Answer 45

polygenic inheritance

Question 46

_______ is when a single gene can affect more than one trait

Answer 46

pleiotrophy

Question 47

________ _______ for one gene is where genes have more than two alleles in a populations

Answer 47

multiple alleles

Question 48

________ dominance shows an intermediate phenotype for the heterzygote

Answer 48

incomplete

Question 49

________, the heterozygote shows some aspect of the phenotypes of both homozygotes

Answer 49

codominance

Question 50

_________ factors is where genes may be affected by the environment

Answer 50

environmental

Question 51

_____ _____ is the products of genes can interact to alter genetic ratios

Answer 51

gene interactions

Question 52

T or F: environment does effect phenotype

Answer 52

True

Question 53

______ ______ refers to different phenotypes from same genotype due to environmental conditions

Answer 53

phenotypic plasticiity

Question 54

________ _______ refers to a range of possible phenotypes across genotypes, the phenotype is the result of an accumulation of contributions by multiple genes

Answer 54

continuous variation

Question 55

_______ ______ is a trait that is determined by the effect of more than one gene

Answer 55

quantitative traits

Question 56

______ ______ heritability is the fraction of phenotypic variation due to underlying genetic variation

Answer 56

broad sense

Question 57

______ _____ heritability is the fraction of phenotypic variation due to additive genetic variance, that is the genetic variance for a specific trait

Answer 57

narrow sense

Question 58

Height is a ______ varying trait

Answer 58

continuously

Question 59

_______ refers to an allele which has more than one effect on the phenotype

Answer 59

pleiotropy

Question 60

Blood type A codes for what sugar?

Answer 60

galactosamine

Question 61

Blood type B codes for what sugar?

Answer 61

galactose

Question 62

Blood type AB codes for what type of sugar?

Answer 62

Galactose and galactosamine

Question 63

Blood type O codes for sugar?

Answer 63

none

Question 64

What blood types are codominant?

Answer 64

A and B

Question 65

_______ is when the action of one gene obscures the effects of another gene

Answer 65

epistasis

Question 66

In labradors what are the two genes that control coat color?

Answer 66

Brown and extension