Question 1

In the frog egg, rotation of the cortical cytoplasm produces the _______, which is a site of important developmental events.

Accepted Answer

The answer of In the frog egg, rotation of the...

Question 2

In human development, an embryo is most sensitive to chemicals, radiation, and pathogens during the first trimester because this is the time when

Accepted Answer

A)  tissues are differentiating. 
B)  organs are increasing in size. 
C)  the fetus grows rapidly. 
D)  fetal movements begin. 
E)  implantation occurs. 
A)  tissues are differentiating. 
B)  organs are increasing in size. 
C)  the fetus grows rapidly. 
D)  fetal movements begin. 
E)  implantation occurs.

Question 3

In birds and placental mammals, the embryo proper forms from the

Accepted Answer

A)  trophoblast. 
B)  chorion. 
C)  amnion. 
D)  epiblast. 
E)  hypoblast. 
A)  trophoblast. 
B)  chorion. 
C)  amnion. 
D)  epiblast. 
E)  hypoblast.

Question 4

Which statement about cleavage in placental mammals is true?

Accepted Answer

A)  The number of cells increases regularly, from 2 to 4 to 8 to 16 to 32, etc. 
B)  It proceeds more quickly than cleavage in frogs. 
C)  It is characterized by synchronous cell divisions. 
D)  It is radial. 
E)  It is influenced by genes that are expressed during cleavage. 
A)  The number of cells increases regularly, from 2 to 4 to 8 to 16 to 32, etc. 
B)  It proceeds more quickly than cleavage in frogs. 
C)  It is characterized by synchronous cell divisions. 
D)  It is radial. 
E)  It is influenced by genes that are expressed during cleavage.

Question 5

After gastrulation, the mesodermal cells contribute to the developing

Accepted Answer

A)  brain. 
B)  bones. 
C)  lining of the digestive tract. 
D)  epidermis. 
E)  liver epithelium. 
A)  brain. 
B)  bones. 
C)  lining of the digestive tract. 
D)  epidermis. 
E)  liver epithelium.

Question 6

Which structure(s) is/are derived primarily from ectoderm?

Accepted Answer

A)  Blood 
B)  Muscle 
C)  Bone 
D)  Heart 
E)  Sweat glands 
A)  Blood 
B)  Muscle 
C)  Bone 
D)  Heart 
E)  Sweat glands

Question 7

The signaling cascades that determine left-right asymmetry of internal organs in humans are caused by extracellular fluid flowing over

Accepted Answer

A)  the epiblast. 
B)  the blastocyst. 
C)  the inner cell mass. 
D)  a node of ciliated cells. 
E)  the hypoblast. 
A)  the epiblast. 
B)  the blastocyst. 
C)  the inner cell mass. 
D)  a node of ciliated cells. 
E)  the hypoblast.

Question 8

Refer to the figure showing stages of gastrulation in the frog.   Which of the following represents the correct sequence of events?

Accepted Answer

A)  A, B, C, D 
B)  A, C, B, D 
C)  C, D, B, A 
D)  D, A, C, B 
E)  D, C, A, B 
A)  A, B, C, D 
B)  A, C, B, D 
C)  C, D, B, A 
D)  D, A, C, B 
E)  D, C, A, B

Question 9

Refer to the figure showing a sea urchin gastrula.   Of the structures labeled a-g in the sea urchin gastrula, which are also found in the amphibian gastrula, and what are the names of these structures?

Accepted Answer

a. Blastocoel
b. Bla

Question 10

A researcher experimentally removes four somites on the right side of a chick embryo, between the wings and hindlimbs.When this chick hatches, it is most likely to have

Accepted Answer

A)  defects in the skull. 
B)  dermis missing on the left side. 
C)  defects in vertebrae in the trunk region. 
D)  nerves missing on both the left and right sides. 
E)  abnormal muscles associated with vertebrae on the left side. 
A)  defects in the skull. 
B)  dermis missing on the left side. 
C)  defects in vertebrae in the trunk region. 
D)  nerves missing on both the left and right sides. 
E)  abnormal muscles associated with vertebrae on the left side.

Question 11

Roundworms exhibit

Accepted Answer

A)  regulative development. 
B)  early restriction of blastomere fates. 
C)  rotational cleavage. 
D)  the ability of cells to compensate for loss of other cells. 
E)  the formation of an amnion during development. 
A)  regulative development. 
B)  early restriction of blastomere fates. 
C)  rotational cleavage. 
D)  the ability of cells to compensate for loss of other cells. 
E)  the formation of an amnion during development.

Question 12

Because the human embryo is able to split during early cleavage or blastocyst formation to produce two viable progeny, it is said to exhibit _______ development.

Accepted Answer

A)  mosaic 
B)  determinative 
C)  indirect 
D)  regulative 
E)  direct 
A)  mosaic 
B)  determinative 
C)  indirect 
D)  regulative 
E)  direct

Question 13

Refer to the figure showing a scanning electron micrograph of a chick embryo and the figure of a frog embryo.   Which correctly matches a structure in the chick embryo with a structure in the frog embryo?

Accepted Answer

A)  1 and d 
B)  2 and a 
C)  3 and c 
D)  4 and b 
E)  5 and e 
A)  1 and d 
B)  2 and a 
C)  3 and c 
D)  4 and b 
E)  5 and e

Question 14

In developing chicks, the first extraembryonic membrane to start forming is the _______.

Accepted Answer

The answer of In developing chicks, the first extraembryonic membrane...

Question 15

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. 
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.

Question 16

Which feature characterizes the sea urchin archenteron?

Accepted Answer

A)  It requires the primary mesenchyme to form. 
B)  It is derived from mesoderm. 
C)  It is elongated by contraction of filopodia extending from secondary mesenchyme. 
D)  The anus forms as a secondary opening. 
E)  Its open end is the blastopore, which becomes the mouth. 
A)  It requires the primary mesenchyme to form. 
B)  It is derived from mesoderm. 
C)  It is elongated by contraction of filopodia extending from secondary mesenchyme. 
D)  The anus forms as a secondary opening. 
E)  Its open end is the blastopore, which becomes the mouth.

Question 17

In vertebrates, the initiation of the nervous system is called _______, and it is an example of _______.

Accepted Answer

A)  neurulation; organogenesis 
B)  gastrulation; organogenesis 
C)  axis formation; body segmentation 
D)  notochord formation; organization 
E)  neurulation; blastula formation 
A)  neurulation; organogenesis 
B)  gastrulation; organogenesis 
C)  axis formation; body segmentation 
D)  notochord formation; organization 
E)  neurulation; blastula formation

Question 18

Which statement about gastrulation in amphibians is true?

Accepted Answer

A)  Gastrulation increases the number of germ layers from one to three. 
B)  The inward movement of mesoderm and endoderm creates the blastocoel. 
C)  Mesoderm forms by epiboly. 
D)  Inwardly moving bottle cells create the dorsal lip of the blastopore. 
E)  Prior to invagination, cells flatten at the vegetal pole. 
A)  Gastrulation increases the number of germ layers from one to three. 
B)  The inward movement of mesoderm and endoderm creates the blastocoel. 
C)  Mesoderm forms by epiboly. 
D)  Inwardly moving bottle cells create the dorsal lip of the blastopore. 
E)  Prior to invagination, cells flatten at the vegetal pole.

Question 19

Which statement about chick development is true?

Accepted Answer

A)  Cells migrate through the primitive groove into the blastocoel to become endoderm and mesoderm. 
B)  Chick embryos lack a blastocoel. 
C)  Hensen's node is located at the posterior end of the primitive groove. 
D)  Gastrulation begins as cells in the anterior region of the epiblast move toward the midline. 
E)  Cells generated in Hensen's node produce the vertebral column, which organizes the embryo along an axis. 
A)  Cells migrate through the primitive groove into the blastocoel to become endoderm and mesoderm. 
B)  Chick embryos lack a blastocoel. 
C)  Hensen's node is located at the posterior end of the primitive groove. 
D)  Gastrulation begins as cells in the anterior region of the epiblast move toward the midline. 
E)  Cells generated in Hensen's node produce the vertebral column, which organizes the embryo along an axis.

Question 20

A man and a woman who are both carriers for cystic fibrosis are using in vitro fertilization and preimplantation genetic diagnosis to ensure their offspring will not be afflicted by cystic fibrosis.In the procedure, a cell is removed from the embryo at the eight-cell stage and analyzed for the mutant genes.An embryo that is not homozygous for the mutation is implanted in the woman and develops normally.Because development is normal in the embryo after a cell has been removed, you can conclude that human development

Accepted Answer

A)  involves autonomous specification of blastomeres. 
B)  is regulative during early cleavage stages. 
C)  is mosaic and cells are determined early in development. 
D)  involves determinants that specify the fates of different blastomeres early in development. 
E)  involves informational molecules produced from the maternal genome and stored in the egg and distributed to different blastomeres. 
A)  involves autonomous specification of blastomeres. 
B)  is regulative during early cleavage stages. 
C)  is mosaic and cells are determined early in development. 
D)  involves determinants that specify the fates of different blastomeres early in development. 
E)  involves informational molecules produced from the maternal genome and stored in the egg and distributed to different blastomeres.

Exam 43: Animal Development

In the frog egg, rotation of the cortical cytoplasm produces the _______, which is a site of important developmental events.

In human development, an embryo is most sensitive to chemicals, radiation, and pathogens during the first trimester because this is the time when

In birds and placental mammals, the embryo proper forms from the

Which statement about cleavage in placental mammals is true?

After gastrulation, the mesodermal cells contribute to the developing

Which structure(s) is/are derived primarily from ectoderm?

The signaling cascades that determine left-right asymmetry of internal organs in humans are caused by extracellular fluid flowing over

Refer to the figure showing stages of gastrulation in the frog. Which of the following represents the correct sequence of events?

Refer to the figure showing a sea urchin gastrula. Of the structures labeled a-g in the sea urchin gastrula, which are also found in the amphibian gastrula, and what are the names of these structures?

A researcher experimentally removes four somites on the right side of a chick embryo, between the wings and hindlimbs.When this chick hatches, it is most likely to have

Roundworms exhibit

Because the human embryo is able to split during early cleavage or blastocyst formation to produce two viable progeny, it is said to exhibit _______ development.

Refer to the figure showing a scanning electron micrograph of a chick embryo and the figure of a frog embryo. Which correctly matches a structure in the chick embryo with a structure in the frog embryo?

In developing chicks, the first extraembryonic membrane to start forming is the _______.

Which feature characterizes the sea urchin archenteron?

In vertebrates, the initiation of the nervous system is called _______, and it is an example of _______.

Which statement about gastrulation in amphibians is true?

Which statement about chick development is true?

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