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| 1 | |
In a species which displays metamorphosis, metamorphosis occurs following |
| | A) | cleavage. |
| | B) | gastrulation. |
| | C) | organogenesis. |
| | D) | fertilization. |
| | E) | neurulation. |
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| 2 | |
Which of the following does not represent a major mechanism of cell differentiation? |
| | A) | autonomous specification |
| | B) | conditional specification |
| | C) | invariable specification |
| | D) | Autonomous specification and conditional specification |
| | E) | Autonomous specification, conditional specification, and invariable specification |
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| 3 | |
Failure of the neural tube to close at either the anterior or posterior end is a condition referred to as |
| | A) | muscular dystrophy. |
| | B) | multiple sclerosis. |
| | C) | cerebral palsy. |
| | D) | anencephaly. |
| | E) | spina bifida. |
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| 4 | |
The so-called fast block to polyspermy prevents the |
| | A) | binding of sperm to egg membrane proteins after the first sperm has fused. |
| | B) | formation of sperm cells in the testes. |
| | C) | combination of maternal and paternal genomes within the zygote nucleus. |
| | D) | rapid propulsion of sperm through the cervix into the uterus. |
| | E) | localization of sperm to externally laid eggs. |
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| 5 | |
Arrange the following events of embryonic development in order from earliest to latest.
I: Cleavage
II: Gastrulation
III: Fertilization
IV: Neurolation
V: Organogenesis |
| | A) | I; III; II; V; IV |
| | B) | III; I; II; IV; V |
| | C) | III; II; I; V; IV |
| | D) | II; III; V; I; IV |
| | E) | V; III; II; IV; I |
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| 6 | |
Which of the following stages of the eukaryotic cell cycle is not represented during cleavage? |
| | A) | G1 |
| | B) | S |
| | C) | G2 |
| | D) | G1 and S |
| | E) | G1, S and G2 |
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| 7 | |
True or False: Because embryonic cells in eutherian mammals are protected from influences in the outer environment, biphasic cleavage of these cells occurs slowly. |
| | A) | True |
| | B) | False |
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| 8 | |
In mammals, the outer layer of a blastocyst is referred to as the __________, and gives rise to the __________. |
| | A) | morula; vegetal pole |
| | B) | trophectoderm; placenta |
| | C) | inner cell mass; embryo |
| | D) | zona pellucida; animal pole |
| | E) | yolk mass; blastula |
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| 9 | |
Which of the following structures is derived from ectoderm? |
| | A) | Notochord |
| | B) | Kidney |
| | C) | Blood |
| | D) | Neurons |
| | E) | Alveoli |
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| 10 | |
Which of the following statements about the archenteron is incorrect? |
| | A) | During gastrulation, the archenteron displaces the blastocoel. |
| | B) | The archenteron is destined to become the digestive tract. |
| | C) | The formation of the archenteron is due to a combination of invagination and involution of cells. |
| | D) | By the end of gastrulation, the opening to the archenteron is filled with a mass of tissue referred to as a yolk plug. |
| | E) | All of the statements about the archenteron are correct. |
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| 11 | |
True or False: The notochord persists in the trunk and tail of birds, amphibians, fishes, and mammals. |
| | A) | True |
| | B) | False |
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| 12 | |
The lineage of cells destined to differentiate into sperm or egg cells is most accurately referred to as |
| | A) | vegetal pole cells. |
| | B) | bottle cells. |
| | C) | primordial germ cells. |
| | D) | follicular cells. |
| | E) | dorsal mesodermal cells. |
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| 13 | |
Arrange the following events of gastrulation in amphibians in order from earliest to latest.
I: archenteron formed by invagination and involution
II: beginning of notochord formation
III: formation of blastopore |
| | A) | I; II; III |
| | B) | III; I; II |
| | C) | III; II; I |
| | D) | II; III; I |
| | E) | I; III; II |
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| 14 | |
All organs are derived from _______________ during organogenesis. |
| | A) | endoderm |
| | B) | mesoderm |
| | C) | ectoderm |
| | D) | primordial germ cells |
| | E) | Different organs are derived from different germ layers. |
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| 15 | |
Which of the following is not an example of conditional specification? |
| | A) | Movement of cytoplasmic molecules through gap junctions |
| | B) | Cell-to-cell signaling by exocytosis of stored messengers |
| | C) | Asymmetric distribution of cytoplasmic factors |
| | D) | Binding of membrane proteins to each other |
| | E) | Cellular induction |
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| 16 | |
True or False: Mesodermal cells tend to only adhere to other mesodermal cells due to differences in cadherin proteins used for cell adherence between germ layer cells. |
| | A) | True |
| | B) | False |
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| 17 | |
Which of the following statements about morphogenetic fields is incorrect? |
| | A) | In insects, morphogenetic fields are called imaginal discs. |
| | B) | Morphogenetic fields in amphibians are believed to be particularly sensitive to environmental pollutants. |
| | C) | Removal of a morphogenetic limb field typically results in the lack of that limb at the correct position. |
| | D) | Spemann's organizer is a morphogenetic field which, when transplanted into a recipient gastrula, leads to development of a second body axis. |
| | E) | All of the statements about morphogenetic fields are correct. |
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| 18 | |
Which of the following statements about the noggin gene and/or Noggin protein is incorrect? |
| | A) | Noggin is found in amphibians and mammals. |
| | B) | Noggin inhibits other morphogens which induce dorsal mesoderm formation. |
| | C) | The noggin gene was discovered from a cDNA library prepared from dorsal lip tissue. |
| | D) | When delivered at high concentrations, noggin mRNA leads to development of excessive amounts of anterior mesoderm and not enough ventral mesoderm. |
| | E) | All of the statements about the noggin gene and/or Noggin protein are correct. |
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| 19 | |
True or False: Transforming Growth Factor betas are important morphogens involved in the induction of ectoderm. |
| | A) | True |
| | B) | False |
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| 20 | |
True or False: The most common genetic disorder affecting humans is Down syndrome. |
| | A) | True |
| | B) | False |
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