Question 1

What is dosage compensation with respect to the sex chromosomes, and how is this accomplished in humans?

Accepted Answer

Dosage combination equalizes the expression of X-linked genes in males and females.The process of dosage compensation involves the random inactivation of one of the two X chromosomes in the female.

Question 2

Which of the following represents the possible genotype(s) resulting from a cross between two individuals that are heterozygous (Bb)?

Accepted Answer

A)  BB and Bb 
B)  BB, Bb, and bb 
C)  BB only 
D)  Bb only 
E)  bb only 
A)  BB and Bb 
B)  BB, Bb, and bb 
C)  BB only 
D)  Bb only 
E)  bb only B

Question 3

Using standard conventions for naming alleles, which of the following pairs is correct?

Accepted Answer

A)  Tt-recessive phenotype. 
B)  TT-heterozygous. 
C)  tt-homozygous. 
D)  tt-dominant phenotype. 
E)  All of these are correct. 
A)  Tt-recessive phenotype. 
B)  TT-heterozygous. 
C)  tt-homozygous. 
D)  tt-dominant phenotype. 
E)  All of these are correct. C

Question 4

A couple has already had 3 girls with cystic fibrosis, and were hoping to have a normal child for their fourth.What are the chances that the fourth child will be a normal male?

Accepted Answer

A)  0 
B)  1/8 
C)  1/4 
D)  3/8 
E)  1/2 
A)  0 
B)  1/8 
C)  1/4 
D)  3/8 
E)  1/2

Question 5

The sex of most mammals, birds, and insects is determined by:

Accepted Answer

A)  the temperature. 
B)  the external environment. 
C)  sex chromosomes. 
D)  chance. 
E)  the internal envronment. 
A)  the temperature. 
B)  the external environment. 
C)  sex chromosomes. 
D)  chance. 
E)  the internal envronment.

Question 6

A particular gene that controls seed coat color in peas also determines the susceptibility of these peas to a particular disease.This situation is referred to as:

Accepted Answer

A)  varigation. 
B)  additive dominance. 
C)  codominance. 
D)  pleiotropy. 
E)  incomplete dominance. 
A)  varigation. 
B)  additive dominance. 
C)  codominance. 
D)  pleiotropy. 
E)  incomplete dominance.

Question 7

The range of phenotypic possibilities that can develop from a certain dog genotype under different environmental conditions is called the:

Accepted Answer

A)  epistatic interaction. 
B)  norm of reaction. 
C)  nurture limit. 
D)  genotype range. 
E)  maximum phenotype. 
A)  epistatic interaction. 
B)  norm of reaction. 
C)  nurture limit. 
D)  genotype range. 
E)  maximum phenotype.

Question 8

Which of the following represents the possible genotype(s) resulting from a cross between an individual heterozygous (Bb) and one that is homozygous (bb)?

Accepted Answer

A)  BB and Bb 
B)  Bb and bb 
C)  BB only 
D)  Bb only 
E)  bb only 
A)  BB and Bb 
B)  Bb and bb 
C)  BB only 
D)  Bb only 
E)  bb only

Question 9

The height of pea plants from a cross between parent plants heterozygous for height, in which tall is dominant, would be:

Accepted Answer

A)  all short. 
B)  all tall. 
C)  1 tall : 3 short. 
D)  2 short : 2 tall. 
E)  3 tall : 1 short. 
A)  all short. 
B)  all tall. 
C)  1 tall : 3 short. 
D)  2 short : 2 tall. 
E)  3 tall : 1 short.

Question 10

Dominant traits remove recessive traits when both are present in the same individual.
__________________

Accepted Answer

A) True 
 B)False

Question 11

A lizard with a striped tail is crossed with one having a spotted head, producing normal looking (no stripes or spots) lizard progeny.What progeny would be expected to be produced by mating these progeny with each other, if the genes conferring stripes and spots were on different chromosomes?

Accepted Answer

A)  equal numbers of normal, striped, spotted and striped, and spotted 
B)  3 striped : 1 spotted 
C)  9 striped and spotted : 3 spotted : 3 striped : 1 normal 
D)  9 striped : 3 spotted : 1 striped or spotted 
E)  9 normal : 3 striped : 3 spotted : 1 striped and spotted 
A)  equal numbers of normal, striped, spotted and striped, and spotted 
B)  3 striped : 1 spotted 
C)  9 striped and spotted : 3 spotted : 3 striped : 1 normal 
D)  9 striped : 3 spotted : 1 striped or spotted 
E)  9 normal : 3 striped : 3 spotted : 1 striped and spotted

Question 12

Mendel verified true-breeding pea plants for certain traits before undertaking his experiments.The term "true-breeding" refers to:

Accepted Answer

A)  genetically pure lines. 
B)  organisms that have a high rate of reproduction. 
C)  organisms that will produce identical copies of themselves upon reproduction. 
D)  organisms that are heterozygous for a given trait. 
E)  organisms that are homozygous for all possible traits. 
A)  genetically pure lines. 
B)  organisms that have a high rate of reproduction. 
C)  organisms that will produce identical copies of themselves upon reproduction. 
D)  organisms that are heterozygous for a given trait. 
E)  organisms that are homozygous for all possible traits.

Question 13

Suppose that the allele for brown eyes (B) is dominant to the allele for hazel eyes (b).If both parents have brown eyes and are heterozygous (Bb), what are the chances that their first child will have hazel eyes? Brown eyes? What are the chances that if they have two children, both will have hazel eyes?

Accepted Answer

Concepts to Consider: The prob

Question 14

If a couple is planning on having two children, what is the probability that both will be male?

Accepted Answer

A)  0 
B)  1/4 
C)  1/2 
D)  3/4 
E)  1 
A)  0 
B)  1/4 
C)  1/2 
D)  3/4 
E)  1

Question 15

MATCHING
a.incomplete
d.pleiotropy
b.codominance
e.polygenic
c.epistasis
-The presence of certain alleles at one locus can prevent or mask the expression of alleles at different locus

Accepted Answer

The answer of MATCHING
a.incomplete
d.pleiotropy
b.codominance
e.polygenic
c.epistasis
-The presence of certain alleles at one...

Question 16

A brown-eyed couple already has a child with blue eyes.What is the probability that their next child will have blue eyes, assuming that the brown eye allele is dominant and the blue eye allele is recessive?

Accepted Answer

A)  0 
B)  1/4 
C)  1/2 
D)  3/4 
E)  1 
A)  0 
B)  1/4 
C)  1/2 
D)  3/4 
E)  1

Question 17

Which of the following represents the possible genotype(s) resulting from a cross between an individual homozygous for black hair (BB) and an individual homozygous for blonde hair (bb)?

Accepted Answer

A)  BB and Bb 
B)  BB, Bb, and bb 
C)  BB only 
D)  Bb only 
E)  bb only 
A)  BB and Bb 
B)  BB, Bb, and bb 
C)  BB only 
D)  Bb only 
E)  bb only

Question 18

What are the possible phenotypes of the children if the mother's genotype is IAi for blood type and the father is IBi? (Use the Punnett square to verify your answer.)

Accepted Answer

A)  all AB 
B)  A, B 
C)  A, AB 
D)  A, B, O 
E)  A, B, AB, O 
A)  all AB 
B)  A, B 
C)  A, AB 
D)  A, B, O 
E)  A, B, AB, O

Question 19

In humans, assume that the allele for brown eyes is dominant and the allele for blue eyes is recessive.If two brown-eyed individuals have a child with blue eyes, that means:

Accepted Answer

A)  both parents are homozygous for brown eyes. 
B)  both parents are heterozygous for eye color. 
C)  there is a 1/4 chance that their second child will have brown eyes. 
D)  there is a 50/50 chance that their second child will have blue eyes. 
E)  there is a 3/4 chance that their second child will have blue eyes 
A)  both parents are homozygous for brown eyes. 
B)  both parents are heterozygous for eye color. 
C)  there is a 1/4 chance that their second child will have brown eyes. 
D)  there is a 50/50 chance that their second child will have blue eyes. 
E)  there is a 3/4 chance that their second child will have blue eyes

Question 20

Mendel's principle of segregation states that:

Accepted Answer

A)  alleles from one parent mask the expression of alleles from the other parent. 
B)  alleles separate from each other before forming gametes. 
C)  hybrids will express a phenotype intermediate between the two parental phenotypes. 
D)  true-breeding parents produce offspring of the same phenotype. 
E)  different loci separate from each other. 
A)  alleles from one parent mask the expression of alleles from the other parent. 
B)  alleles separate from each other before forming gametes. 
C)  hybrids will express a phenotype intermediate between the two parental phenotypes. 
D)  true-breeding parents produce offspring of the same phenotype. 
E)  different loci separate from each other.

Exam 11: The Basic Principles of Heredity

What is dosage compensation with respect to the sex chromosomes, and how is this accomplished in humans?

Which of the following represents the possible genotype(s) resulting from a cross between two individuals that are heterozygous (Bb)?

Using standard conventions for naming alleles, which of the following pairs is correct?

A couple has already had 3 girls with cystic fibrosis, and were hoping to have a normal child for their fourth.What are the chances that the fourth child will be a normal male?

The sex of most mammals, birds, and insects is determined by:

A particular gene that controls seed coat color in peas also determines the susceptibility of these peas to a particular disease.This situation is referred to as:

The range of phenotypic possibilities that can develop from a certain dog genotype under different environmental conditions is called the:

Which of the following represents the possible genotype(s) resulting from a cross between an individual heterozygous (Bb) and one that is homozygous (bb)?

The height of pea plants from a cross between parent plants heterozygous for height, in which tall is dominant, would be:

Dominant traits remove recessive traits when both are present in the same individual. __________________

A lizard with a striped tail is crossed with one having a spotted head, producing normal looking (no stripes or spots) lizard progeny.What progeny would be expected to be produced by mating these progeny with each other, if the genes conferring stripes and spots were on different chromosomes?

Mendel verified true-breeding pea plants for certain traits before undertaking his experiments.The term "true-breeding" refers to:

If a couple is planning on having two children, what is the probability that both will be male?

MATCHING a.incomplete d.pleiotropy b.codominance e.polygenic c.epistasis -The presence of certain alleles at one locus can prevent or mask the expression of alleles at different locus

A brown-eyed couple already has a child with blue eyes.What is the probability that their next child will have blue eyes, assuming that the brown eye allele is dominant and the blue eye allele is recessive?

Which of the following represents the possible genotype(s) resulting from a cross between an individual homozygous for black hair (BB) and an individual homozygous for blonde hair (bb)?

What are the possible phenotypes of the children if the mother's genotype is IAi for blood type and the father is IBi? (Use the Punnett square to verify your answer.)

In humans, assume that the allele for brown eyes is dominant and the allele for blue eyes is recessive.If two brown-eyed individuals have a child with blue eyes, that means:

Mendel's principle of segregation states that:

A View of Life

Atoms and Molecules: the Chemical Basis of Life

The Chemistry of Life: Organic Compounds

Organization of the Cell

Biological Membranes

Cell Communication

Energy and Metabolism

How Cells Make Atp: Energy-Releasing Pathways

Photosynthesis: Capturing Light Energy

Chromosomes, Mitosis, and Meiosis

Dna: the Carrier of Genetic Information

Gene Expression

Gene Regulation

Dna Technology and Genomics

Human Genetics and the Human Genome

Developmental Genetics

Introduction to Darwinian Evolution

Evolutionary Change in Populations

Speciation and Macroevolution

The Origin and Evolutionary History of Life

The Evolution of Primates

Understanding Diversity: Systematics

Viruses and Subviral Agents

Bacteria and Archaea

Protists

Seedless Plants

Seed Plants

The Fungi

An Introduction to Animal Diversity

Sponges, Cnidarians, Ctenophores, and Protostomes

The Deuterostomes

Plant Structure, Growth, and Development

Leaf Structure and Function

Stem Structure and Transport

Roots and Mineral Nutrition

Reproduction in Flowering Plants

Plant Developmental Responses to External and Internal Signals

Animal Structure and Function: an Introduction

Protection, Support, and Movement

Neural Signaling

Neural Regulation

Sensory Systems

Internal Transport

The Immune System: Internal Defense

Gas Exchange

Processing Food and Nutrition

Osmoregulation and Disposal of Metabolic Wastes

Endocrine Regulation

Reproduction

Animal Development

Animal Behavior

Introduction to Ecology: Population Ecology

Community Ecology

Ecosystems and the Biosphere

Ecology and the Geography of Life

Biological Diversity and Conservation Biology

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What are the possible phenotypes of the children if the mother's genotype is I^Ai for blood type and the father is I^Bi? (Use the Punnett square to verify your answer.)