Question 1

Which feature is characteristic of development in organisms whose eggs have little to a moderate amount of yolk?

Accepted Answer

A)   Incomplete cleavage
B)   Discoidal cleavage
C)   Embryos that form as blastodiscs
D)   A yolk mass below the embryo
E)   Early cleavage furrows that divide the egg completelyF) C) and D)
G) A) and C)

Question 2

The gray crescent in a frog zygote

Accepted Answer

A)   marks the site of important developmental events.
B)   develops at the site of sperm entry.
C)   causes rotation of the cortical cytoplasm.
D)   does not change in position from its location in the unfertilized egg.
E)   results from rotation of the heavily pigmented inner cytoplasm relative to the less pigmented cortical cytoplasm.F) All of the above
G) A) and C)

Question 3

Which structure in birds and mammals is the equivalent of the dorsal lip of the amphibian blastopore?

Accepted Answer

A)   Blastocoel
B)   Hensen's node
C)   Primitive groove
D)   Epiblast
E)   HypoblastF) A) and D)
G) A) and E)

Question 4

Refer to the graph.  In the graph, curve _______ best represents the changes in the ratio of nuclear volume to cytoplasmic volume during early cleavage in most animals.At this time, the blastomeres _______ in size.

Accepted Answer

A)   A; decrease
B)   B; decrease
C)   C; decrease
D)   A; increase
E)   C; increaseF) C) and D)
G) B) and E)

Question 5

A man who suffers from a mitochondrial disease due to a mutation in his mitochondrial DNA is worried he will pass this defect on to his children.A genetic counselor tells the man that there is a negligible probability of his passing this disease on to his offspring, because mitochondria are inherited from the _______.

Accepted Answer

The answer of A man who suffers from a mitochondrial...

Question 6

An obstetrician can listen to the heartbeat of a fetus to determine the health of the heart and whether there is a multiple pregnancy.In which trimester of the pregnancy will the obstetrician first be able to hear the baby's heartbeat? Explain your answer.

Accepted Answer

The first trimester,...

Question 7

Refer to the figure showing a stage of gastrulation in the frog.  Consider a piece of ectoderm that is destined to be neural tissue in its original location in the gastrula shown in the figure.If it is transplanted into a location destined to be epidermis in a gastrula of similar age, which of the following will result?

Accepted Answer

A)   The transplanted tissue will develop into neural tissue.
B)   The transplanted tissue will develop into dermis.
C)   The transplant will be rejected.
D)   The transplanted tissue will develop into epidermis.
E)   A second complete embryo will form belly-to-belly with the recipient of the transplant.F) B) and D)
G) A) and B)

Question 8

In each somite there are several regions of cells that give rise to different structures.Experimental destruction of one somite would impair the development of

Accepted Answer

A)   muscles, cartilage of vertebrae, and the inner layer of skin (dermis) .
B)   the lining of the reproductive tract and lungs.
C)   the pancreas and lungs.
D)   pigment cells, the jaw, and smooth muscle.
E)   the brain, skull, and dermis of the face.F) A) and B)
G) A) and C)

Question 9

Which statement about germ cells is true?

Accepted Answer

A)   Cells that later give rise to gametes arise in the gonads.
B)   Oocytes and spermatocytes are reproductive stem cells.
C)   Cells with germ cell plasm originally reside in the animal hemisphere in frogs.
D)   Molecules in the cytoplasm of the egg determine which cells become germ cells.
E)   Germ cell plasm contains substances that promote differentiation during cleavage stages.F) B) and E)
G) A) and D)

Question 10

You are observing a video of development in Xenopus (African clawed frog).Immediately following the segment on gastrulation, the video shows neural crest cells migrating toward their destinations, and you realize that the segment showing _______ is missing.

Accepted Answer

The answer of You are observing a video of development...

Question 11

A researcher experimentally blocks the protein that inhibits GSK-3 in a frog zygote.Which would be the most immediate effect?

Accepted Answer

A)   GSK-3 would be degraded throughout the cytoplasm.
B)   β-catenin would be degraded throughout the cytoplasm.
C)   GSK-3 would become localized in the region of the gray crescent.
D)   β-catenin would be present throughout the cytoplasm.
E)   β-catenin would be more concentrated in the dorsal cells of the early embryo.F) None of the above
G) B) and C)

Question 12

If a researcher inhibited formation of filopodia during sea urchin gastrulation, which of the following would be least likely to form?

Accepted Answer

A)   Anus
B)   Primary mesenchyme
C)   Secondary mesenchyme
D)   Mouth
E)   BlastoporeF) A) and E)
G) B) and D)

Question 13

The region of the frog egg with dark pigmentation, where fertilization can take place, is known as the _______ hemisphere.

Accepted Answer

The answer of The region of the frog egg with...

Question 14

Which statement about Hox genes in mammals is true?

Accepted Answer

A)   Genes closest to the 5′ end of each gene complex are expressed first and in the posterior part of the embryo.
B)   Hox genes provide information leading to sensory nerve connections developing in the dorsal region of the spinal cord and motor nerve connections developing in the ventral region.
C)   Each of the Hox gene complexes has about four genes.
D)   Genes closest to the 3′ end of each gene complex are expressed later and in the posterior part of the embryo.
E)   Hox genes control body segmentation.F) B) and E)
G) A) and B)

Question 15

Refer to the figure showing a 9-day chick embryo.  Match the following terms with their label numbers in the figure: allantoic membrane, allantois, amnion, body of embryo, chorion, and yolk sac.

Accepted Answer

Allantoic membrane: ...

Question 16

Although details of gastrulation differ among sea urchins, frogs, and chickens, there is a common result in all of these animals.What is it?

Accepted Answer

The common result is the forma...

Question 17

An embryo exhibits abnormal development in the most posterior part of its body.The responsible Hox gene is located

Accepted Answer

A)   close to the 3′ end of the Hox gene complex.
B)   at the 5′ end of the Hox gene complex.
C)   in the middle of the Hox gene complex.
D)   at the 3′ end of the Hox gene complex.
E)   in another gene complex.F) C) and E)
G) A) and B)

Question 18

Which result did Hans Spemann and Hilde Mangold get when they transplanted the dorsal lip of the blastopore of an early amphibian gastrula to the belly region of another early gastrula?

Accepted Answer

A)   The transplanted tissue was rejected.
B)   The recipient of the transplant died.
C)   A second site of gastrulation was stimulated, but that embryo died.
D)   A secondary embryo formed belly-to-belly with the first embryo.
E)   The transplanted tissue passed through gastrulation only to form an incomplete embryo.F) C) and E)
G) C) and D)

Question 19

Which statement about developing placental mammals is true?

Accepted Answer

A)   The epiblast forms the amnion, which encloses the embryo in a fluid-filled sac.
B)   The epiblast forms the yolk sac, which contributes to the formation of the chorion.
C)   The allantois is only found in species in which the placenta does not readily remove nitrogenous wastes from the fetus.
D)   Fetal and maternal blood directly mix at the placenta.
E)   The amnion contributes to the umbilical cord, which connects the embryo to the placenta.F) A) and E)
G) C) and D)

Question 20

The centriole of the sperm becomes the _______ of the zygote.

Accepted Answer

The answer of The centriole of the sperm becomes the...

Exam 43: Animal Development

The centriole of the sperm becomes the _______ of the zygote.

Correct Answer
verified

An obstetrician can listen to the heartbeat of a fetus to determine the health of the heart and whether there is a multiple pregnancy.In which trimester of the pregnancy will the obstetrician first be able to hear the baby's heartbeat? Explain your answer.

Correct Answer
verified
The first trimester,...
View Answer

Refer to the figure showing a 9-day chick embryo. Match the following terms with their label numbers in the figure: allantoic membrane, allantois, amnion, body of embryo, chorion, and yolk sac.

Correct Answer
verified
Allantoic membrane: ...
View Answer

Which feature is characteristic of development in organisms whose eggs have little to a moderate amount of yolk?

Correct Answer
verified

Although details of gastrulation differ among sea urchins, frogs, and chickens, there is a common result in all of these animals.What is it?

Correct Answer
verified
The common result is the forma...
View Answer

Which structure in birds and mammals is the equivalent of the dorsal lip of the amphibian blastopore?

Correct Answer
verified

The gray crescent in a frog zygote

Correct Answer
verified

An embryo exhibits abnormal development in the most posterior part of its body.The responsible Hox gene is located

Correct Answer
verified

The region of the frog egg with dark pigmentation, where fertilization can take place, is known as the _______ hemisphere.

Correct Answer
verified

If a researcher inhibited formation of filopodia during sea urchin gastrulation, which of the following would be least likely to form?

Correct Answer
verified

You are observing a video of development in Xenopus (African clawed frog).Immediately following the segment on gastrulation, the video shows neural crest cells migrating toward their destinations, and you realize that the segment showing _______ is missing.

Correct Answer
verified

Correct Answer
verified

Which result did Hans Spemann and Hilde Mangold get when they transplanted the dorsal lip of the blastopore of an early amphibian gastrula to the belly region of another early gastrula?

Correct Answer
verified

Refer to the graph. In the graph, curve _ best represents the changes in the ratio of nuclear volume to cytoplasmic volume during early cleavage in most animals.At this time, the blastomeres _ in size.

Correct Answer
verified

Which statement about developing placental mammals is true?

Correct Answer
verified

In each somite there are several regions of cells that give rise to different structures.Experimental destruction of one somite would impair the development of

Correct Answer
verified

A researcher experimentally blocks the protein that inhibits GSK-3 in a frog zygote.Which would be the most immediate effect?

Correct Answer
verified

Which statement about germ cells is true?

Correct Answer
verified

Correct Answer
verified

Which statement about Hox genes in mammals is true?

Correct Answer
verified

Exam 43: Animal Development

The centriole of the sperm becomes the _______ of the zygote.

Correct AnswerverifiedShow Answer

An obstetrician can listen to the heartbeat of a fetus to determine the health of the heart and whether there is a multiple pregnancy.In which trimester of the pregnancy will the obstetrician first be able to hear the baby's heartbeat? Explain your answer.

Correct AnswerverifiedThe first trimester,...View AnswerShow Answer

Refer to the figure showing a 9-day chick embryo. Match the following terms with their label numbers in the figure: allantoic membrane, allantois, amnion, body of embryo, chorion, and yolk sac.

Correct AnswerverifiedAllantoic membrane: ...View AnswerShow Answer

Which feature is characteristic of development in organisms whose eggs have little to a moderate amount of yolk?

Correct AnswerverifiedShow Answer

Although details of gastrulation differ among sea urchins, frogs, and chickens, there is a common result in all of these animals.What is it?

Correct AnswerverifiedThe common result is the forma...View AnswerShow Answer

Which structure in birds and mammals is the equivalent of the dorsal lip of the amphibian blastopore?

Correct AnswerverifiedShow Answer

The gray crescent in a frog zygote

Correct AnswerverifiedShow Answer

An embryo exhibits abnormal development in the most posterior part of its body.The responsible Hox gene is located

Correct AnswerverifiedShow Answer

The region of the frog egg with dark pigmentation, where fertilization can take place, is known as the _______ hemisphere.

Correct AnswerverifiedShow Answer

If a researcher inhibited formation of filopodia during sea urchin gastrulation, which of the following would be least likely to form?

Correct AnswerverifiedShow Answer

You are observing a video of development in Xenopus (African clawed frog).Immediately following the segment on gastrulation, the video shows neural crest cells migrating toward their destinations, and you realize that the segment showing _______ is missing.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which result did Hans Spemann and Hilde Mangold get when they transplanted the dorsal lip of the blastopore of an early amphibian gastrula to the belly region of another early gastrula?

Correct AnswerverifiedShow Answer

Refer to the graph. In the graph, curve _______ best represents the changes in the ratio of nuclear volume to cytoplasmic volume during early cleavage in most animals.At this time, the blastomeres _______ in size.

Correct AnswerverifiedShow Answer

Which statement about developing placental mammals is true?

Correct AnswerverifiedShow Answer

In each somite there are several regions of cells that give rise to different structures.Experimental destruction of one somite would impair the development of

Correct AnswerverifiedShow Answer

A researcher experimentally blocks the protein that inhibits GSK-3 in a frog zygote.Which would be the most immediate effect?

Correct AnswerverifiedShow Answer

Which statement about germ cells is true?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which statement about Hox genes in mammals is true?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
The first trimester,...
View Answer

Correct Answer
verified
Allantoic membrane: ...
View Answer

Correct Answer
verified

Correct Answer
verified
The common result is the forma...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Refer to the graph. In the graph, curve _ best represents the changes in the ratio of nuclear volume to cytoplasmic volume during early cleavage in most animals.At this time, the blastomeres _ in size.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified