Question 1

Suppose that a parent has a genotype of RrYy. What is the probability of this parent producing a gamete with the RY genotype?

Accepted Answer

A)  3 in 4 
B)  1 in 2 
C)  1 in 4 
D)  1 in 8 
A)  3 in 4 
B)  1 in 2 
C)  1 in 4 
D)  1 in 8 C

Question 2

Mendel performed a testcross with his plants and all the resulting progeny had the same colour. What information did this testcross provide?

Accepted Answer

A)  The parent with the dominant trait is homozygous. 
B)  The parent with the dominant trait is heterozygous. 
C)  The parent with the recessive trait is heterozygous. 
D)  The parent with the recessive trait is homozygous. 
A)  The parent with the dominant trait is homozygous. 
B)  The parent with the dominant trait is heterozygous. 
C)  The parent with the recessive trait is heterozygous. 
D)  The parent with the recessive trait is homozygous. A

Question 3

Suppose the probability of X occurring is 1 in 4, and the probability of Y occurring is 1 in 5. What is the probability of both occurring?

Accepted Answer

A)  (1/4) + (1/5) = (5/20) + (4/20) = 9/20 
B)  (1/4)2 + (1/5)2 = (1/16) + (1/25) = (25/400) + (16/400) = 41/400 
C)  (1/4) × (1/5) = 1/20 
D)  (1/4)2 × (1/5)2 = (1/16) × (1/25) = 1/400 
A)  (1/4) + (1/5) = (5/20) + (4/20) = 9/20 
B)  (1/4)2 + (1/5)2 = (1/16) + (1/25) = (25/400) + (16/400) = 41/400 
C)  (1/4) × (1/5) = 1/20 
D)  (1/4)2 × (1/5)2 = (1/16) × (1/25) = 1/400 C

Question 4

Suppose that your mother and father both have cystic fibrosis, which is caused by a recessive allele. What are the odds of you having only one allele for the disorder?

Accepted Answer

A)  1 
B)  1 in 2 
C)  1 in 4 
D)  0 
A)  1 
B)  1 in 2 
C)  1 in 4 
D)  0

Question 5

Suppose that your mother and father both have cystic fibrosis, which is caused by a recessive allele. What are the odds of you having cystic fibrosis?

Accepted Answer

A)  1 
B)  3 in 4 
C)  1 in 2 
D)  1 in 4 
A)  1 
B)  3 in 4 
C)  1 in 2 
D)  1 in 4

Question 6

Suppose that an F1 dihybrid cross results in a phenotypic ratio of 9:3:4. What does this tell you?

Accepted Answer

A)  The second locus is dominant over the first locus. 
B)  Dominance is incomplete at the second locus. 
C)  Epistasis is occurring. 
D)  Codominance is at the second locus. 
A)  The second locus is dominant over the first locus. 
B)  Dominance is incomplete at the second locus. 
C)  Epistasis is occurring. 
D)  Codominance is at the second locus.

Question 7

Snapdragons have incomplete dominance of the red and white alleles. What will be the phenotypes and ratios of the F2 generation?

Accepted Answer

A)  100% pink 
B)  100% red 
C)  50% white, 50% red 
D)  25% white, 25% red, 50% pink 
A)  100% pink 
B)  100% red 
C)  50% white, 50% red 
D)  25% white, 25% red, 50% pink

Question 8

According to the blending theory of inheritance that predominated before 1900, what colour of progeny would result from the mating of a white flower and a red flower?

Accepted Answer

A)  white 
B)  pink 
C)  red 
D)  some white, others red 
A)  white 
B)  pink 
C)  red 
D)  some white, others red

Question 9

Suppose that your mother has albinism, which is a recessive trait. Also suppose your father has cystic fibrosis, which is also caused by a recessive trait. And you learn that your father-in-law has albinism and cystic fibrosis. What are the odds that your first child will have either albinism or cystic fibrosis, but NOT both?

Accepted Answer

A)  3 in 8 
B)  1 in 4 
C)  1 in 8 
D)  1 in 16 
A)  3 in 8 
B)  1 in 4 
C)  1 in 8 
D)  1 in 16

Question 10

Suppose that your father has B blood and your mother has O blood. You learn that your blood is also type O. What does this tell you?

Accepted Answer

A)  You were adopted and your parents did not tell you. 
B)  You inherited one parent's blood type but not the other parent's blood type. 
C)  Your father's genotype is IBIB and your mother's genotype is ii. 
D)  Your father's genotype is IBi and your mother's genotype is ii. 
A)  You were adopted and your parents did not tell you. 
B)  You inherited one parent's blood type but not the other parent's blood type. 
C)  Your father's genotype is IBIB and your mother's genotype is ii. 
D)  Your father's genotype is IBi and your mother's genotype is ii.

Question 11

Which of the following best identifies the "White Bear" in Northern British Columbia?

Accepted Answer

A)  a giant raccoon 
B)  a blonde version of the grizzly bear 
C)  a blonde version of the black bear 
D)  a polar bear 
A)  a giant raccoon 
B)  a blonde version of the grizzly bear 
C)  a blonde version of the black bear 
D)  a polar bear

Question 12

Suppose your mother has albinism, which is a recessive trait. Suppose also that your father has cystic fibrosis, which is also caused by a recessive trait. And, you learn that your father-in-law has albinism and cystic fibrosis. What are the odds that your first child will have both albinism and cystic fibrosis?

Accepted Answer

A)  1 in 2 
B)  1 in 4 
C)  1 in 8 
D)  1 in 16 
A)  1 in 2 
B)  1 in 4 
C)  1 in 8 
D)  1 in 16

Question 13

Suppose that your blood type is B. Which of these alleles do you most likely carry in your body?

Accepted Answer

A)  only IB, or IB and i 
B)  only i, or IB and i 
C)  only IA, or IA and i 
D)  only i, or IA and i 
A)  only IB, or IB and i 
B)  only i, or IB and i 
C)  only IA, or IA and i 
D)  only i, or IA and i

Question 14

Would meiosis, when it was discovered, have been understood without Mendel's work? Explain why or why not, using Mendel's three key findings about inheritance.

Accepted Answer

No, meiosis would not have been understo

Question 15

An F1 organism is always homozygous.

Accepted Answer

A) True 
 B)False

Question 16

Match the examples listed below to the following five types of allele interactions.
-Peas being wrinkled or round is an example of this.

Accepted Answer

A) dominance 
B) incomplete dominance 
C) codominance 
D) epistasis 
E) polygenic inheritance 
A) dominance 
B) incomplete dominance 
C) codominance 
D) epistasis 
E) polygenic inheritance

Question 17

What is the key difference between incomplete dominance and codominance?

Accepted Answer

A)  With incomplete dominance, the recessive allele cannot be detected; in codominance, the expression of the recessive allele is apparent. 
B)  With codominance, it is possible to detect the expression of a recessive allele; in incomplete dominance, both alleles contribute equally to the phenotype. 
C)  With incomplete dominance, it is possible to detect the expression of the dominant allele; in codominance, both alleles contribute equally to the phenotype. 
D)  With incomplete dominance, it is possible to detect the expression of a recessive allele; in codominance, both alleles contribute equally to the phenotype. 
A)  With incomplete dominance, the recessive allele cannot be detected; in codominance, the expression of the recessive allele is apparent. 
B)  With codominance, it is possible to detect the expression of a recessive allele; in incomplete dominance, both alleles contribute equally to the phenotype. 
C)  With incomplete dominance, it is possible to detect the expression of the dominant allele; in codominance, both alleles contribute equally to the phenotype. 
D)  With incomplete dominance, it is possible to detect the expression of a recessive allele; in codominance, both alleles contribute equally to the phenotype.

Question 18

Match each term with its correct definition.
-dihybrid

Accepted Answer

A) displayed traits are unchanged over multiple generations 
B) first generation of offspring from a parental cross 
C) true-breeding organisms used in the initial cross 
D) result of a cross between two first-generation organisms 
E) allele that is expressed no matter what other allele is present
F)allele that is expressed only if two identical copies are present
G)any organism with two identical copies of an allele
H)any organism with two different forms of an allele
I)F1 heterozygote (for a single trait)
J)genetic makeup of an organism
K)physical traits of an organism
L)likelihood of something occurring if the occurrence is a matter of chance
M)organism that is heterozygous for two different traits
N)where an allele is found on a chromosome
O)when one allele cannot completely mask the effects of another allele
P)alleles at one locus mask the expression of alleles at a different locus
Q)several different genes contribute to a particular phenotype
R)single allele has multiple phenotypic effects 
A) displayed traits are unchanged over multiple generations 
B) first generation of offspring from a parental cross 
C) true-breeding organisms used in the initial cross 
D) result of a cross between two first-generation organisms 
E) allele that is expressed no matter what other allele is present
F)allele that is expressed only if two identical copies are present
G)any organism with two identical copies of an allele
H)any organism with two different forms of an allele
I)F1 heterozygote (for a single trait)
J)genetic makeup of an organism
K)physical traits of an organism
L)likelihood of something occurring if the occurrence is a matter of chance
M)organism that is heterozygous for two different traits
N)where an allele is found on a chromosome
O)when one allele cannot completely mask the effects of another allele
P)alleles at one locus mask the expression of alleles at a different locus
Q)several different genes contribute to a particular phenotype
R)single allele has multiple phenotypic effects

Question 19

Match the examples listed below to the following five types of allele interactions.
-Human height is an example of this.

Accepted Answer

A) dominance 
B) incomplete dominance 
C) codominance 
D) epistasis 
E) polygenic inheritance 
A) dominance 
B) incomplete dominance 
C) codominance 
D) epistasis 
E) polygenic inheritance

Question 20

Which sentence describes the principle of independent assortment?

Accepted Answer

A)  Genes on the same chromosome are always inherited together. 
B)  Two alleles for a single trait are randomly sorted to individual gametes; chromosomes are not mentioned. 
C)  Alleles on different homologous chromosomes are not randomly sorted to individual gametes. 
D)  Genes on the same chromosome are not randomly sorted to different gametes. 
A)  Genes on the same chromosome are always inherited together. 
B)  Two alleles for a single trait are randomly sorted to individual gametes; chromosomes are not mentioned. 
C)  Alleles on different homologous chromosomes are not randomly sorted to individual gametes. 
D)  Genes on the same chromosome are not randomly sorted to different gametes.

Exam 9: The Chromosomal Basis of Mendelian Inheritance

Suppose that a parent has a genotype of RrYy. What is the probability of this parent producing a gamete with the RY genotype?

Mendel performed a testcross with his plants and all the resulting progeny had the same colour. What information did this testcross provide?

Suppose the probability of X occurring is 1 in 4, and the probability of Y occurring is 1 in 5. What is the probability of both occurring?

Suppose that your mother and father both have cystic fibrosis, which is caused by a recessive allele. What are the odds of you having only one allele for the disorder?

Suppose that your mother and father both have cystic fibrosis, which is caused by a recessive allele. What are the odds of you having cystic fibrosis?

Suppose that an F1 dihybrid cross results in a phenotypic ratio of 9:3:4. What does this tell you?

Snapdragons have incomplete dominance of the red and white alleles. What will be the phenotypes and ratios of the F2 generation?

According to the blending theory of inheritance that predominated before 1900, what colour of progeny would result from the mating of a white flower and a red flower?

Suppose that your father has B blood and your mother has O blood. You learn that your blood is also type O. What does this tell you?

Which of the following best identifies the "White Bear" in Northern British Columbia?

Suppose that your blood type is B. Which of these alleles do you most likely carry in your body?

Would meiosis, when it was discovered, have been understood without Mendel's work? Explain why or why not, using Mendel's three key findings about inheritance.

An F1 organism is always homozygous.

Match the examples listed below to the following five types of allele interactions. -Peas being wrinkled or round is an example of this.

What is the key difference between incomplete dominance and codominance?

Match each term with its correct definition. -dihybrid

Match the examples listed below to the following five types of allele interactions. -Human height is an example of this.

Which sentence describes the principle of independent assortment?

Light and Life

The Cell: an Overview

Energy and Enzymes

Cell Membranes and Signaling

Cellular Respiration

Photosynthesis

Cell Cycles

Genetic Recombination

Genetic Linkage, Sex-Linkage, and Other Non-Mendelian Inheritance Mechanisms

DNA Structure, Replication, and Repair

Gene Structure Expression, and Mutation

Regulation of Gene Expression

Dna Technologies

Genomes

Evolution: the Development of the Theory

Microevolution: Changes Within Populations

Speciation and Macroevolution

Systematics and Phylogenetics: Revealing the Tree of Life

Humans and Evolution

Defining Life and Its Origins

Viruses, Viroids, and Prions: Infectious Biological Particles

Bacteria and Archaea

Protists

Fungi

Plants

Animals

Conservation of Biodiversity

Population Ecology

Species Interactions and Community Ecology

Ecosystems

Animal Behaviour

Organization of the Plant Body

Transport in Plants

Reproduction and Development in Flowering Plants

Plant Nutrition

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Animal Nutrition

Gas Exchange: the Respiratory System

Internal Transport: the Circulatory System

Regulation of the Internal Environment: Water, Solutes, and Temperature

Control of Animal Processes: Endocrine Control

Animal Reproduction

Control of Animal Processes: Neural Control

Muscles, Skeletons, and Body Movements

Filters

Suppose that an F₁ dihybrid cross results in a phenotypic ratio of 9:3:4. What does this tell you?

Snapdragons have incomplete dominance of the red and white alleles. What will be the phenotypes and ratios of the F₂ generation?

An F₁ organism is always homozygous.