Question 1

The effect of yolk on cleavage is that

Accepted Answer

A)  yolk promotes faster cleavage.
B)  yolk promotes spiral cleavage in all cases.
C)  yolk slows down and indirectly determines the type of cleavage to take place.
D)  yolk is the origin of all cleavage planes.E) C) and D)
F) B) and C)

Question 2

The difference between schizocoelous and enterocoelus organisms is

Accepted Answer

A)  no difference at all;they are two names for the same eucoelomate structure.
B)  a difference in how the true coelom forms from mesoderm,from the gut or blastopore region.
C)  the difference between a pseudocoelom and a true coelom.
D)  a difference between a split two-chambered coelom and an intact or enterocoelom.E) All of the above
F) None of the above

Question 3

The concept that an egg or sperm cell contained a very small but fully developed individual was called

Accepted Answer

A)  induction.
B)  pronuclei.
C)  preformation.
D)  holoblastism.E) A) and D)
F) C) and D)

Question 4

The allantois

Accepted Answer

A)  becomes the chorionic villi.
B)  lies next to the shell in chicks.
C)  is a structure composed of two germ layers.
D)  gives rise to umbilical blood vessels in humans.E) A) and B)
F) A) and C)

Question 5

The cortical reaction that follows fertilization causes a hardening of the vitelline envelope to produce the _________ _________.

Accepted Answer

fertilizat...

Question 6

A primitive streak appears during gastrulation of

Accepted Answer

A)  sea stars and humans.
B)  birds and reptiles.
C)  nemerteans.
D)  only mammals.E) B) and C)
F) A) and D)

Question 7

The placenta develops from

Accepted Answer

A)  fetal membranes only.
B)  maternal tissue only.
C)  both fetal and maternal tissue.
D)  polar bodies that develop just the placental tissues.E) A) and C)
F) C) and D)

Question 8

In land vertebrates,the function of the chorion is to

Accepted Answer

A)  become umbilical cord.
B)  enclose the entire embryonic system and then fuse to form the chorioallantoic membrane.
C)  grow from the embryonic hindgut to become a repository for the wastes of metabolism.
D)  surround the embryo and provide a marine environment for development.E) C) and D)
F) B) and D)

Question 9

An enterocoelous animal has

Accepted Answer

A)  a true coelom.
B)  a pseudocoelom.
C)  no coelom.
D)  a schizocoelom.E) None of the above
F) A) and B)

Question 10

Throughout the descriptions of the various major animal taxa,the type of cleavage and the origin of the coelom are of foremost importance.Why are such esoteric developmental features central to classification compared to other prominent anatomical and physiological features that are only mentioned for a few major taxa?

Accepted Answer

The type of cleavage and the origin of t...

Question 11

Evolutionary Developmental Biology (Evo-Devo) is a relatively new field that links the study of evolution to the study of development.Which statement below is best supported by the emerging principles of Evo-Devo?

Accepted Answer

A)  The common ancestor to protostomes and deuterostomes likely had rudimentary eyes.This has been determined by studying the genes associated with eye development from these groups and finding a gene that is identical regardless of the species studied.
B)  The bilaterally symmetrical animals all appear to be similar with only minor changes in the genes that form the nervous system.These changes are responsible for animal diversity through the use of different inductive strategies.
C)  The dorsoventral patterning genes,studied in various protostome and deuterostome lineages,demonstrate that these groups used convergent evolution to obtain similar developmental processes.
D)  The rapid evolution of new animal body forms may rely less on numerous,small mutations and more on a few mutations in genes that regulate development.E) A) and B)
F) A) and C)

Question 12

When the central mass of yolk restricts cleavage to the surface of the egg,and 8 rounds of mitosis without cytoplasmic division pepper the surface with nuclei that eventually are enclosed,this is ______ cleavage.

Accepted Answer

A)  radial
B)  spiral
C)  superficial
D)  trophoblasticE) A) and B)
F) A) and C)

Question 13

In mammals,the organ of exchange between the mother and fetus is the

Accepted Answer

A)  amnion.
B)  placenta.
C)  chorion.
D)  yolk sac.E) A) and B)
F) A) and C)

Question 14

Entrance of more than one sperm

Accepted Answer

A)  is called polyspermy and is disastrous for animal zygotes.
B)  results in epigenesis.
C)  is neutralized by fusion with polar bodies.
D)  results in formation of a large pronucleus.
E)  initiates cleavage.F) A) and B)
G) C) and D)

Question 15

In animals,indirect development

Accepted Answer

A)  occurs only in mammals.
B)  lacks a larval stage.
C)  involves a larval stage.
D)  occurs only when eggs develop without being fertilized.E) B) and C)
F) A) and B)

Question 16

The sac that surrounds the fetus and usually ruptures just before childbirth is the

Accepted Answer

A)  amnion.
B)  placenta.
C)  chorion.
D)  yolk sac.
E)  allantois.F) B) and C)
G) A) and B)

Question 17

Which of the following is NOT characteristic of regulative development in animals?

Accepted Answer

A)  is a type in which removing a blastomere causes the remaining blastomeres to "fill in" for the lost cell.
B)  usually occurs in protostomes.
C)  occurs in most (but not all) deuterostomes.
D)  is a type in which the fate of a blastomere is heavily determined by its neighbor cells.E) B) and C)
F) A) and D)

Question 18

A developmental stage comprised of a hollow ball of cells is the

Accepted Answer

A)  blastula.
B)  blastocoel.
C)  gastrula.
D)  neurula.E) A) and C)
F) A) and B)

Question 19

The nervous system of vertebrates develops from which germ layer?

Accepted Answer

A)  Epiderm
B)  Ectoderm
C)  Endoderm
D)  Mesoderm
E)  MyodermF) C) and D)
G) A) and D)

Question 20

A characteristic of development of Deuterostomia is

Accepted Answer

A)  spiral cleavage.
B)  mosaic development.
C)  the mesoderm developing from a special blastomere called the 4d cell.
D)  radial cleavage.E) All of the above
F) A) and C)

Exam 8: Principles of Development

Evolutionary Developmental Biology (Evo-Devo) is a relatively new field that links the study of evolution to the study of development.Which statement below is best supported by the emerging principles of Evo-Devo?

Correct Answer
verified

In mammals,the organ of exchange between the mother and fetus is the

Correct Answer
verified

A developmental stage comprised of a hollow ball of cells is the

Correct Answer
verified

When the central mass of yolk restricts cleavage to the surface of the egg,and 8 rounds of mitosis without cytoplasmic division pepper the surface with nuclei that eventually are enclosed,this is ______ cleavage.

Correct Answer
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A characteristic of development of Deuterostomia is

Correct Answer
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An enterocoelous animal has

Correct Answer
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The allantois

Correct Answer
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Which of the following is NOT characteristic of regulative development in animals?

Correct Answer
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The concept that an egg or sperm cell contained a very small but fully developed individual was called

Correct Answer
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The placenta develops from

Correct Answer
verified

In land vertebrates,the function of the chorion is to

Correct Answer
verified

In animals,indirect development

Correct Answer
verified

The nervous system of vertebrates develops from which germ layer?

Correct Answer
verified

The sac that surrounds the fetus and usually ruptures just before childbirth is the

Correct Answer
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The difference between schizocoelous and enterocoelus organisms is

Correct Answer
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The cortical reaction that follows fertilization causes a hardening of the vitelline envelope to produce the _ _.

Correct Answer
verified
fertilizat...
View Answer

A primitive streak appears during gastrulation of

Correct Answer
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Correct Answer
Answered by ExamLex AI
The type of cleavage and the origin of t...
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The effect of yolk on cleavage is that

Correct Answer
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Entrance of more than one sperm

Correct Answer
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Exam 8: Principles of Development

Evolutionary Developmental Biology (Evo-Devo) is a relatively new field that links the study of evolution to the study of development.Which statement below is best supported by the emerging principles of Evo-Devo?

Correct AnswerverifiedShow Answer

In mammals,the organ of exchange between the mother and fetus is the

Correct AnswerverifiedShow Answer

A developmental stage comprised of a hollow ball of cells is the

Correct AnswerverifiedShow Answer

When the central mass of yolk restricts cleavage to the surface of the egg,and 8 rounds of mitosis without cytoplasmic division pepper the surface with nuclei that eventually are enclosed,this is ______ cleavage.

Correct AnswerverifiedShow Answer

A characteristic of development of Deuterostomia is

Correct AnswerverifiedShow Answer

An enterocoelous animal has

Correct AnswerverifiedShow Answer

The allantois

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Which of the following is NOT characteristic of regulative development in animals?

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The concept that an egg or sperm cell contained a very small but fully developed individual was called

Correct AnswerverifiedShow Answer

The placenta develops from

Correct AnswerverifiedShow Answer

In land vertebrates,the function of the chorion is to

Correct AnswerverifiedShow Answer

In animals,indirect development

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The nervous system of vertebrates develops from which germ layer?

Correct AnswerverifiedShow Answer

The sac that surrounds the fetus and usually ruptures just before childbirth is the

Correct AnswerverifiedShow Answer

The difference between schizocoelous and enterocoelus organisms is

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The cortical reaction that follows fertilization causes a hardening of the vitelline envelope to produce the _________ _________.

Correct Answerverifiedfertilizat...View AnswerShow Answer

A primitive streak appears during gastrulation of

Correct AnswerverifiedShow Answer

Correct AnswerAnswered by ExamLex AIThe type of cleavage and the origin of t...View AnswerShow Answer

The effect of yolk on cleavage is that

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Entrance of more than one sperm

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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
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The cortical reaction that follows fertilization causes a hardening of the vitelline envelope to produce the _ _.

Correct Answer
verified
fertilizat...
View Answer

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
The type of cleavage and the origin of t...
View Answer

Correct Answer
verified

Correct Answer
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