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| 1 | |
Enzymes associated with the _____ of the sperm help the sperm penetrate the egg. |
| | A) | head |
| | B) | tail |
| | C) | midpiece |
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| 2 | |
Gastrulation is complete when _____. |
| | A) | the blastocoel develops |
| | B) | three layers of cells are present |
| | C) | the egg nucleus fuses with the sperm nucleus |
| | D) | the ectoderm and endoderm are present |
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| 3 | |
The _____ is the outer germ layer. |
| | A) | ectoderm |
| | B) | endoderm |
| | C) | mesoderm |
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| 4 | |
Which of the choices is the correct order of embryonic stages?
1. Blastula
2. Zygote
3. Morula
4. Gastrula
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| | A) | 3, 2, 1, 4 |
| | B) | 2, 4, 3, 1 |
| | C) | 2, 3, 1, 4 |
| | D) | 3, 2, 4, 1 |
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| 5 | |
The _____ is a cavity in the blastula. |
| | A) | blastocoel |
| | B) | coelom |
| | C) | hemocoel |
| | D) | archenteron |
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| 6 | |
Uterine contractions which expel the fetus are initiated by _____. |
| | A) | prostaglandins |
| | B) | oxytocin |
| | C) | androgens |
| | D) | All of these |
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| 7 | |
The last major organ(s) to develop completely is/are the _____. |
| | A) | lungs |
| | B) | liver |
| | C) | kidneys |
| | D) | heart |
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| 8 | |
The baby is delivered during stage _____ of parturition. |
| | A) | one |
| | B) | two |
| | C) | three |
| | D) | four |
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| 9 | |
In humans, the _____ become(s) the thymus gland and parathyroids. |
| | A) | notochord |
| | B) | umbilical cord |
| | C) | pharyngeal arches |
| | D) | limb buds |
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| 10 | |
The developing eyes, ears and nose can be distinguished as early as the _____ week of gestation. |
| | A) | second |
| | B) | fifth |
| | C) | twelfth |
| | D) | twentieth |
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| 11 | |
The blood vessels of the _____ become the umbilical blood vessels. |
| | A) | chorion |
| | B) | allantois |
| | C) | amnion |
| | D) | yolk sac |
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| 12 | |
The trophoblast produces _____, which maintains the corpus luteum and prevents menstruation. |
| | A) | estrogen |
| | B) | inhibin |
| | C) | follicle stimulating hormone |
| | D) | human chorionic gonadotropin |
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| 13 | |
Fertilization occurs in the _____. |
| | A) | oviduct |
| | B) | uterus |
| | C) | vagina |
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| 14 | |
The organization of differentiated cells into specific three-dimensional structures is controlled by _____. |
| | A) | morphogens |
| | B) | bicoid genes |
| | C) | homeotic genes |
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| 15 | |
The Hox genes _______. |
| | A) | are located on a single chromosome in humans and mice |
| | B) | greatly vary from species to species |
| | C) | are expressed from anterior to posterior in the same order in humans, mice and Drosophila |
| | D) | All of these |
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| 16 | |
When a receptor protein binds a cell-death signal, _____. |
| | A) | the master ced protein is inactivated |
| | B) | apoptosis occurs |
| | C) | proteases and nucleases that slice up proteins and DNA in the cell are produced |
| | D) | All of these |
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| 17 | |
The ability of one embryonic tissue to influence the development of another tissue is called _____. |
| | A) | morphogenesis |
| | B) | gastrulation |
| | C) | induction |
| | D) | differentiation |
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| 18 | |
The adult vertebrate's nervous system arose from the _____. |
| | A) | ectoderm |
| | B) | mesoderm |
| | C) | endoderm |
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| 19 | |
Which of the following adult vertebrate structures developed from the mesoderm? |
| | A) | Skeleton |
| | B) | Cardiovascular system |
| | C) | Dermis of the skin |
| | D) | All of these |
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| 20 | |
In the frog, the developing coelom is completely lined with _____. |
| | A) | endoderm |
| | B) | ectoderm |
| | C) | mesoderm |
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