Question 1

Experimental depletion of β-catenin mRNA transcripts in amphibian embryos results in

Accepted Answer

A)  failure of cleavage to occur. 
B)  induction of a second axis of embryo formation. 
C)  failure of gastrulation to occur. 
D)  failure of invagination to occur. 
E)  slowing down of the cleavage process. 
A)  failure of cleavage to occur. 
B)  induction of a second axis of embryo formation. 
C)  failure of gastrulation to occur. 
D)  failure of invagination to occur. 
E)  slowing down of the cleavage process.

Question 2

If a chick embryo has a defect that prevents blood vessels from forming in its extraembryonic mesoderm, which extraembryonic membrane(s) will be affected?

Accepted Answer

A)  Amnion only 
B)  Chorion only 
C)  Allantois only 
D)  Both chorion and yolk sac 
E)  Both allantois and yolk sac 
A)  Amnion only 
B)  Chorion only 
C)  Allantois only 
D)  Both chorion and yolk sac 
E)  Both allantois and yolk sac

Question 3

A blockage in the umbilical vein would prevent the flow of blood from the _______ to the fetus.

Accepted Answer

The answer of A blockage in the umbilical vein would...

Question 4

The process by which the neural plate folds upward to form the neural tube is called _______.The neural tube will then go on to form the brain and spinal cord.

Accepted Answer

The answer of The process by which the neural plate...

Question 5

Refer to the figure showing implantation in humans.   Based on the figure, which statement is true?

Accepted Answer

A)  Gene transcription can occur at points 2 and 3. 
B)  Point 3 is the site where implantation typically occurs. 
C)  Point 4 is a potential site for an ectopic pregnancy. 
D)  Early cleavage occurs at point 4. 
E)  The blastocyst typically hatches from the zona pellucida before point 3. 
A)  Gene transcription can occur at points 2 and 3. 
B)  Point 3 is the site where implantation typically occurs. 
C)  Point 4 is a potential site for an ectopic pregnancy. 
D)  Early cleavage occurs at point 4. 
E)  The blastocyst typically hatches from the zona pellucida before point 3.

Question 6

Which event occurs after the first trimester of human development?

Accepted Answer

A)  Formation of a blastocyst 
B)  Formation of the placenta 
C)  Completion of lung maturation 
D)  Implantation 
E)  Gastrulation 
A)  Formation of a blastocyst 
B)  Formation of the placenta 
C)  Completion of lung maturation 
D)  Implantation 
E)  Gastrulation

Question 7

Which statement about early development in vertebrates is true?

Accepted Answer

A)  Failure of the neural folds to fuse in the anterior region of the developing neural tube results in anencephaly. 
B)  Gastrulation follows organogenesis. 
C)  The notochord is formed from neural ectoderm and provides structural support to the developing embryo. 
D)  Neural crest cells form the neural tube. 
E)  Failure of the neural folds to fuse in the posterior region of the developing neural tube is often linked to a deficiency in vitamin D. 
A)  Failure of the neural folds to fuse in the anterior region of the developing neural tube results in anencephaly. 
B)  Gastrulation follows organogenesis. 
C)  The notochord is formed from neural ectoderm and provides structural support to the developing embryo. 
D)  Neural crest cells form the neural tube. 
E)  Failure of the neural folds to fuse in the posterior region of the developing neural tube is often linked to a deficiency in vitamin D.

Question 8

Suppose you are designing an embryology lab and want to expose your students to as many different patterns of cleavage as possible.Which combination of animals would be the most appropriate to include?

Accepted Answer

A)  Frog, snail, bird, fish, fruit fly 
B)  Snail, bird, lizard, fruit fly, eutherian mammal 
C)  Frog, bird, fish, fruit fly, eutherian mammal 
D)  Frog, fish, lizard, snail, fruit fly 
E)  Frog, snail, bird, fruit fly, eutherian mammal 
A)  Frog, snail, bird, fish, fruit fly 
B)  Snail, bird, lizard, fruit fly, eutherian mammal 
C)  Frog, bird, fish, fruit fly, eutherian mammal 
D)  Frog, fish, lizard, snail, fruit fly 
E)  Frog, snail, bird, fruit fly, eutherian mammal

Question 9

The structure in birds and placental mammals that is most equivalent to the dorsal lip of the frog blastopore is

Accepted Answer

A)  the primitive groove. 
B)  the archenteron. 
C)  the yolk plug. 
D)  Hensen's node. 
E)  the epiblast. 
A)  the primitive groove. 
B)  the archenteron. 
C)  the yolk plug. 
D)  Hensen's node. 
E)  the epiblast.

Question 10

Which of the following does not characterize identical twins in mammals?

Accepted Answer

A)  They are formed either during cleavage or in the early blastula stage. 
B)  They are described as monozygotic. 
C)  Blastomeres physically separate into two groups. 
D)  They have a 50 percent chance of being the same sex. 
E)  When separation of inner cell mass is incomplete, conjoined twins result. 
A)  They are formed either during cleavage or in the early blastula stage. 
B)  They are described as monozygotic. 
C)  Blastomeres physically separate into two groups. 
D)  They have a 50 percent chance of being the same sex. 
E)  When separation of inner cell mass is incomplete, conjoined twins result.

Question 11

In both birds and placental mammals, the embryo forms from the epiblast, and the _______ contributes to extraembryonic membranes.

Accepted Answer

The answer of In both birds and placental mammals, the...

Question 12

The pole cells are the first cells to form in the developing fruit fly embryo.If a researcher removed these cells in a male fruit fly embryo, the adult fly that eventually developed would have testes and (would/would not) _______ produce sperm.

Accepted Answer

The answer of The pole cells are the first cells...

Question 13

Whereas _______ contributes to the _______, _______ contributes to the _______.

Accepted Answer

A)  endoderm; lining of the respiratory tract; ectoderm; heart muscles 
B)  endoderm; nervous system; mesoderm; bones and muscles 
C)  ectoderm; teeth; endoderm; dermal layer of the skin 
D)  endoderm; lining of the digestive tract; mesoderm; epidermis 
E)  ectoderm; nervous system; mesoderm; bones and muscles 
A)  endoderm; lining of the respiratory tract; ectoderm; heart muscles 
B)  endoderm; nervous system; mesoderm; bones and muscles 
C)  ectoderm; teeth; endoderm; dermal layer of the skin 
D)  endoderm; lining of the digestive tract; mesoderm; epidermis 
E)  ectoderm; nervous system; mesoderm; bones and muscles

Question 14

During gastrulation in amphibian embryos, the movement of cells from the animal hemisphere to the site of involution is called _______.

Accepted Answer

The answer of During gastrulation in amphibian embryos, the movement...

Question 15

Which statement about the organizer of amphibians is true?

Accepted Answer

A)  Organizer cells are located in the dorsal lip of the blastopore. 
B)  Organizer cells that involute early produce the same growth factor antagonists as those that involute late. 
C)  The first organizer cells to involute migrate posteriorly and induce structures of the trunk and tail. 
D)  As organizer cells migrate, they act on other cells by activating but not suppressing gene expression in other cells. 
E)  Later organizer cells involute and induce structures of the head. 
A)  Organizer cells are located in the dorsal lip of the blastopore. 
B)  Organizer cells that involute early produce the same growth factor antagonists as those that involute late. 
C)  The first organizer cells to involute migrate posteriorly and induce structures of the trunk and tail. 
D)  As organizer cells migrate, they act on other cells by activating but not suppressing gene expression in other cells. 
E)  Later organizer cells involute and induce structures of the head.

Question 16

A woman in her second month of pregnancy has a miscarriage and is told that her developing embryo had implanted successfully but had poorly developed umbilical blood vessels.Which is the most likely cause of this malformation?

Accepted Answer

A)  A malformed zona pellucida 
B)  Insufficient enzyme produced by the embryo to allow the blastocyst to hatch from its encapsulating extracellular layer 
C)  A malfunction of the endometrium 
D)  A defect in the extraembryonic membranes, such as the chorion and allantois 
E)  A defect in the yolk sac 
A)  A malformed zona pellucida 
B)  Insufficient enzyme produced by the embryo to allow the blastocyst to hatch from its encapsulating extracellular layer 
C)  A malfunction of the endometrium 
D)  A defect in the extraembryonic membranes, such as the chorion and allantois 
E)  A defect in the yolk sac

Question 17

In the mammalian blastocyst, pluripotent stem cells are found in the _______.

Accepted Answer

The answer of In the mammalian blastocyst, pluripotent stem cells...

Question 18

The sperm contributes _______ to the zygote.

Accepted Answer

A)  a nucleus only 
B)  half of the mitochondria and a nucleus 
C)  a centriole and a nucleus 
D)  cilium and a nucleus 
E)  a centrosome only 
A)  a nucleus only 
B)  half of the mitochondria and a nucleus 
C)  a centriole and a nucleus 
D)  cilium and a nucleus 
E)  a centrosome only

Question 19

Approximately how many different Hox genes do mammals possess?

Accepted Answer

A)  4 
B)  10 
C)  40 
D)  400 
E)  4,000 
A)  4 
B)  10 
C)  40 
D)  400 
E)  4,000

Question 20

Failure of blood vessels to form around the yolk sac of a developing chick most likely signals that the _______ is impaired.

Accepted Answer

A)  yolk 
B)  endoderm 
C)  ectoderm 
D)  hypoblast 
E)  mesoderm 
A)  yolk 
B)  endoderm 
C)  ectoderm 
D)  hypoblast 
E)  mesoderm

Exam 43: Animal Development

Experimental depletion of β-catenin mRNA transcripts in amphibian embryos results in

If a chick embryo has a defect that prevents blood vessels from forming in its extraembryonic mesoderm, which extraembryonic membrane(s) will be affected?

A blockage in the umbilical vein would prevent the flow of blood from the _______ to the fetus.

The process by which the neural plate folds upward to form the neural tube is called _______.The neural tube will then go on to form the brain and spinal cord.

Refer to the figure showing implantation in humans. Based on the figure, which statement is true?

Which event occurs after the first trimester of human development?

Which statement about early development in vertebrates is true?

Suppose you are designing an embryology lab and want to expose your students to as many different patterns of cleavage as possible.Which combination of animals would be the most appropriate to include?

The structure in birds and placental mammals that is most equivalent to the dorsal lip of the frog blastopore is

Which of the following does not characterize identical twins in mammals?

In both birds and placental mammals, the embryo forms from the epiblast, and the _______ contributes to extraembryonic membranes.

The pole cells are the first cells to form in the developing fruit fly embryo.If a researcher removed these cells in a male fruit fly embryo, the adult fly that eventually developed would have testes and (would/would not) _______ produce sperm.

Whereas _______ contributes to the _______, _______ contributes to the _______.

During gastrulation in amphibian embryos, the movement of cells from the animal hemisphere to the site of involution is called _______.

Which statement about the organizer of amphibians is true?

A woman in her second month of pregnancy has a miscarriage and is told that her developing embryo had implanted successfully but had poorly developed umbilical blood vessels.Which is the most likely cause of this malformation?

In the mammalian blastocyst, pluripotent stem cells are found in the _______.

The sperm contributes _______ to the zygote.

Approximately how many different Hox genes do mammals possess?

Failure of blood vessels to form around the yolk sac of a developing chick most likely signals that the _______ is impaired.

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Communities

Ecosystems

A Changing Biosphere

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Whereas ___ contributes to the _, _ contributes to the ___.