Question 1

Refer to the figure showing some of the manipulations carried out by Spemann on developing amphibians.  Do the results of these experiments on salamander development indicate that gray crescent material is necessary for normal development? Do these results indicate that gray crescent material is sufficient for normal development? Explain your answer.

Accepted Answer

The two experiments together do indicate...

Question 2

Which structure(s)  would be directly impaired by experimental destruction of somites?

Accepted Answer

A)   Vertebrae
B)   Pancreas
C)   Lungs
D)   Epidermis
E)   StomachF) D) and E)
G) A) and B)

Question 3

Which feature characterizes β-catenin in frogs?

Accepted Answer

A)   It can act as a transcription factor.
B)   It is not present in the unfertilized egg.
C)   It is found in lower concentrations in the gray crescent of a recently fertilized egg.
D)   It is synthesized by glycogen synthase kinase-3 (GSK-3) .
E)   It is found in higher concentrations on the ventral side of the embryo.F) C) and E)
G) B) and D)

Question 4

Which feature characterizes the centriole contributed to the zygote by the sperm?

Accepted Answer

A)   It is one of several nonnuclear organelles contributed by the sperm.
B)   It fuses with the egg's centriole.
C)   It becomes the zygote's centrosome, which organizes mitotic spindles.
D)   It is destroyed once it enters the egg cytoplasm, meaning all centrioles are maternally inherited.
E)   It inhibits cytoplasmic reorganization following fertilization.F) C) and E)
G) A) and B)

Question 5

During cleavage, the positions of the mitotic spindles

Accepted Answer

A)   determine planes of cleavage.
B)   are usually random.
C)   are defined by cytoplasmic factors produced during early cleavage stages.
D)   are unrelated to the organization of the blastomeres.
E)   are similar in radially and spirally cleaving embryos.F) A) and B)
G) C) and D)

Question 6

Which characterizes development in placental mammals but not birds?

Accepted Answer

A)   Epiblast cells migrate through the primitive groove to become endoderm and mesoderm.
B)   The embryo proper forms from the epiblast.
C)   The hypoblast contributes to extraembryonic membranes.
D)   Signaling molecules in Hensen's node are similar to those found in the frog organizer.
E)   Cleavage produces a blastocyst with an inner cell mass.F) None of the above
G) C) and D)

Question 7

_______ is a birth defect caused by failure of the posterior region of the neural tube to close completely.

Accepted Answer

The answer of _______ is a birth defect caused by...

Question 8

Which mammal is most likely to have the shortest gestation period?

Accepted Answer

A)   Horse
B)   Rat
C)   Cow
D)   Cat
E)   DogF) A) and B)
G) A) and E)

Question 9

Refer to the figure showing Hox gene expression in the mouse embryo.  From this figure you can conclude that

Accepted Answer

A)   only one Hoxb gene is expressed in the anterior region of the embryo.
B)   more Hoxb genes are expressed in the posterior region of the embryo than in the anterior region.
C)   Hoxb9 gene is only expressed in the posterior region of the spinal cord.
D)   Hoxb4 gene is expressed in a more posterior region than Hoxb2.
E)   Hoxb2 expression is higher in the spinal cord than the hindbrain.F) B) and D)
G) C) and D)

Question 10

Fertilization

Accepted Answer

A)   allows several sperm to enter before the egg sets up blocks against entry by additional sperm.
B)   prevents ion fluxes across the egg cell membrane.
C)   initiates a rapid series of cell divisions.
D)   decreases the egg's metabolism.
E)   changes protein synthesis without changing the pH of the egg cytoplasm.F) None of the above
G) All of the above

Question 11

The best time to conduct an obstetric ultrasound to evaluate the period of rapid fetal growth in humans is

Accepted Answer

A)   during the middle of the first trimester.
B)   after the formation of the placenta.
C)   after the formation of the limbs.
D)   in the third trimester.
E)   when the heart begins to beat.F) B) and E)
G) A) and E)

Question 12

If the endoderm cells that line the archenteron in a developing frog are altered, this will cause changes in

Accepted Answer

A)   the lining of the digestive tract.
B)   the sense organs.
C)   structures derived from skin.
D)   the heart and blood vessels.
E)   muscles and bones.F) D) and E)
G) C) and E)

Question 13

Which statement about human prenatal development is true?

Accepted Answer

A)   Exposure to drugs or radiation is most harmful during the third trimester.
B)   By the end of the first month, the developing human is considered a fetus.
C)   At 4 weeks gestation, most of the embryo's organ systems have formed.
D)   Growth occurs most rapidly during the first trimester.
E)   Internal organs such as the lungs are mature by the end of the second trimester.F) C) and D)
G) B) and E)

Question 14

You find some marine eggs that were recently laid.The eggs are small with clear cytoplasm.You stain one egg for yolk and find faint staining relatively evenly distributed throughout the cytoplasm.When cleavage begins in the unstained eggs, you are not surprised to see that the pattern of cleavage is

Accepted Answer

A)   spiral.
B)   discoidal.
C)   incomplete.
D)   superficial.
E)   rotational.F) C) and D)
G) A) and D)

Question 15

If you experimentally delete one somite from the right side of a developing chick embryo, which of the following will likely be affected in the chick when it hatches?

Accepted Answer

A)   Left region of the brain
B)   Peripheral nerves in one region on the right side
C)   Notochord in the region of the deleted somite
D)   Muscles and ribs in one region on the left side
E)   Right chambers of the heartF) All of the above
G) A) and C)

Question 16

Why would exposure to a harmful chemical during the first trimester be more likely to produce a major birth defect in a developing human than exposure to the same chemical during the last trimester?

Accepted Answer

Tissues and organs are forming...

Question 17

Which statement about embryonic development is true?

Accepted Answer

A)   Determination is the process by which blastomeres differentiate into specific cell types.
B)   Preimplantation genetic diagnosis is possible in humans because they have regulative development.
C)   In Drosophila, pole cells are the last cells to become determined.
D)   Determination occurs later in species with mosaic development than in species with regulative development.
E)   If the cells of a roundworm embryo in the two-cell stage are separated, each will develop into a complete animal.F) B) and E)
G) B) and C)

Question 18

Which of the following is an extraembryonic membrane correctly paired with its function in the developing chick?

Accepted Answer

A)   Yolk sac: encloses yolk that will be digested in the gut of the embryo
B)   Allantoic membrane: forms a sac that stores fecal wastes
C)   Amnion: secretes a protective fluid that surrounds the embryo
D)   Chorion: allows for transport of water between the embryo and the outside environment
E)   Trophoblast: forms the outermost extraembryonic membrane that protects the embryoF) None of the above
G) All of the above

Question 19

You examine an embryo that has just started to gastrulate and see that there is a deep indentation at the vegetal pole where the sheet of cells is bending inward.From this you are able to determine that this (is/is not) _______ an amphibian embryo.

Accepted Answer

The answer of You examine an embryo that has just...

Question 20

In a cross section of a vertebrate embryo that has just completed neurulation, which is the correct order of structures and tissues encountered, starting at the dorsal surface and moving inward along the midline?

Accepted Answer

A)   Epidermis, notochord, neural tube, gut
B)   Epidermis, neural tube, notochord, gut
C)   Epidermis, vertebral column, gut, neural tube
D)   Epidermis, neural tube, vertebral column, gut
E)   Epidermis, vertebral column, neural tube, gutF) C) and D)
G) B) and E)

Exam 43: Animal Development

Which characterizes development in placental mammals but not birds?

Correct Answer
verified

Refer to the figure showing Hox gene expression in the mouse embryo. From this figure you can conclude that

Correct Answer
verified

Which feature characterizes the centriole contributed to the zygote by the sperm?

Correct Answer
verified

_______ is a birth defect caused by failure of the posterior region of the neural tube to close completely.

Correct Answer
verified

In a cross section of a vertebrate embryo that has just completed neurulation, which is the correct order of structures and tissues encountered, starting at the dorsal surface and moving inward along the midline?

Correct Answer
verified

Which statement about embryonic development is true?

Correct Answer
verified

You find some marine eggs that were recently laid.The eggs are small with clear cytoplasm.You stain one egg for yolk and find faint staining relatively evenly distributed throughout the cytoplasm.When cleavage begins in the unstained eggs, you are not surprised to see that the pattern of cleavage is

Correct Answer
verified

Which statement about human prenatal development is true?

Correct Answer
verified

Fertilization

Correct Answer
verified

Correct Answer
verified
The two experiments together do indicate...
View Answer

Which structure(s) would be directly impaired by experimental destruction of somites?

Correct Answer
verified

Why would exposure to a harmful chemical during the first trimester be more likely to produce a major birth defect in a developing human than exposure to the same chemical during the last trimester?

Correct Answer
verified
Tissues and organs are forming...
View Answer

Which feature characterizes β-catenin in frogs?

Correct Answer
verified

Which mammal is most likely to have the shortest gestation period?

Correct Answer
verified

If the endoderm cells that line the archenteron in a developing frog are altered, this will cause changes in

Correct Answer
verified

If you experimentally delete one somite from the right side of a developing chick embryo, which of the following will likely be affected in the chick when it hatches?

Correct Answer
verified

During cleavage, the positions of the mitotic spindles

Correct Answer
verified

Which of the following is an extraembryonic membrane correctly paired with its function in the developing chick?

Correct Answer
verified

The best time to conduct an obstetric ultrasound to evaluate the period of rapid fetal growth in humans is

Correct Answer
verified

You examine an embryo that has just started to gastrulate and see that there is a deep indentation at the vegetal pole where the sheet of cells is bending inward.From this you are able to determine that this (is/is not) _______ an amphibian embryo.

Correct Answer
verified

Exam 43: Animal Development

Which characterizes development in placental mammals but not birds?

Correct AnswerverifiedShow Answer

Refer to the figure showing Hox gene expression in the mouse embryo. From this figure you can conclude that

Correct AnswerverifiedShow Answer

Which feature characterizes the centriole contributed to the zygote by the sperm?

Correct AnswerverifiedShow Answer

_______ is a birth defect caused by failure of the posterior region of the neural tube to close completely.

Correct AnswerverifiedShow Answer

In a cross section of a vertebrate embryo that has just completed neurulation, which is the correct order of structures and tissues encountered, starting at the dorsal surface and moving inward along the midline?

Correct AnswerverifiedShow Answer

Which statement about embryonic development is true?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which statement about human prenatal development is true?

Correct AnswerverifiedShow Answer

Fertilization

Correct AnswerverifiedShow Answer

Correct AnswerverifiedThe two experiments together do indicate...View AnswerShow Answer

Which structure(s) would be directly impaired by experimental destruction of somites?

Correct AnswerverifiedShow Answer

Why would exposure to a harmful chemical during the first trimester be more likely to produce a major birth defect in a developing human than exposure to the same chemical during the last trimester?

Correct AnswerverifiedTissues and organs are forming...View AnswerShow Answer

Which feature characterizes β-catenin in frogs?

Correct AnswerverifiedShow Answer

Which mammal is most likely to have the shortest gestation period?

Correct AnswerverifiedShow Answer

If the endoderm cells that line the archenteron in a developing frog are altered, this will cause changes in

Correct AnswerverifiedShow Answer

If you experimentally delete one somite from the right side of a developing chick embryo, which of the following will likely be affected in the chick when it hatches?

Correct AnswerverifiedShow Answer

During cleavage, the positions of the mitotic spindles

Correct AnswerverifiedShow Answer

Which of the following is an extraembryonic membrane correctly paired with its function in the developing chick?

Correct AnswerverifiedShow Answer

The best time to conduct an obstetric ultrasound to evaluate the period of rapid fetal growth in humans is

Correct AnswerverifiedShow Answer

You examine an embryo that has just started to gastrulate and see that there is a deep indentation at the vegetal pole where the sheet of cells is bending inward.From this you are able to determine that this (is/is not) _______ an amphibian embryo.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The two experiments together do indicate...
View Answer

Correct Answer
verified

Correct Answer
verified
Tissues and organs are forming...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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