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1 | |
Which of the following series of events represents the path of vertebrate development? |
| | A) | formation of blastula, cleavage, neurulation, cell migration, gastrulation, organogenesis, growth |
| | B) | formation of blastula, cleavage, gastrulation, neurulation, cell migration, organogenesis, growth |
| | C) | cleavage, formation of blastula, gastrulation, neurulation, cell migration, organogenesis, growth |
| | D) | cleavage, gastrulation, formation of blastula, neurulation, cell migration, organogenesis, growth |
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2 | |
Which of the following statements about Drosophila development is FALSE? |
| | A) | Drosophila go through four larval instar stages before undergoing metamorphosis. |
| | B) | During the syncytial blastoderm stage, nuclei line up along the surface of the egg. |
| | C) | Imaginal discs are groups of cells set aside that will give rise to key parts of the adult fly. |
| | D) | Maternal, rather than zygotic, genes govern early Drosophila development. |
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3 | |
If a plant embryo failed to form enough ground tissue, what function(s) would likely be directly affected in the corresponding mature plant? |
| | A) | seed formation |
| | B) | meristem development |
| | C) | cotyledon formation |
| | D) | food and water storage |
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4 | |
C. elegans is a powerful developmental model because |
| | A) | these nematodes are very small, so it is easy to maintain a large population in a laboratory. |
| | B) | the fate of every cell has been mapped. |
| | C) | the fate of cells that will become eggs and sperm are predetermined. |
| | D) | these nematodes have the same amount of DNA as Drosophila. |
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5 | |
Which of the following best describes a morphogen? |
| | A) | a cell that secretes diffusible signaling molecules that play a role in specifying cell fate |
| | B) | a diffusible signaling molecule that plays a role in specifying cell fate |
| | C) | a protein that helps mediate direct cell-cell interaction |
| | D) | a protein that enables cells to become totipotent |
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6 | |
What would happen as a result of a transplantation experiment in a chick embryo in which cells determined to become a forelimb were replaced by some cells determined to become a hindlimb? |
| | A) | A hindlimb would form in the region where the forelimb should be. |
| | B) | A forelimb would form in the region where the hindlimb should be. |
| | C) | Nothing; the forelimb would form normally. |
| | D) | Neither a forelimb nor a hindlimb would form because the cells were already determined. |
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7 | |
Which group of genes, identified by Nusslein-Volhard and Caroll, is responsible for the final stages of segmentation in Drosophila embryos? |
| | A) | morphogen gradient genes |
| | B) | gap genes |
| | C) | segment-polarity genes |
| | D) | pair-rule genes |
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8 | |
Suppose that during a mutagenesis screen to isolate mutations in Drosophila, you came across a fly with legs growing out of its head. What gene cluster is likely affected? |
| | A) | Bicoid |
| | B) | Hunchback |
| | C) | Bithorax |
| | D) | Antennapedia |
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9 | |
What would be the likely result of a mutation of the bcl-2 gene on the level of apoptosis? |
| | A) | no change |
| | B) | a decrease in apoptosis |
| | C) | an increase in apoptosis |
| | D) | First it would increase, but later it would decrease. |
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10 | |
The gene clock hypothesis is best described by which of the following explanations? |
| | A) | Mutations accumulate partially through the addition of an -OH group to the base guanine. |
| | B) | Specific genes exist to promote longevity. |
| | C) | Free radicals can cause genetic mutations, particularly when we are sleeping. |
| | D) | Calorie restriction leads to an increased life span. |
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