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1 | |
One human ejaculation delivers about ____ sperm. |
| | A) | 100 thousand |
| | B) | 100 million |
| | C) | 100 billion |
| | D) | an unknown quantity |
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2 | |
Egg and sperm are |
| | A) | monoploid. |
| | B) | haploid. |
| | C) | diploid. |
| | D) | triploid. |
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3 | |
A diploid cell containing eight chromosomes undergoes meiosis. How many chromosomes are present in the cell after meiosis I? |
| | A) | 2 |
| | B) | 4 |
| | C) | 8 |
| | D) | 16 |
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4 | |
A diploid cell containing eight chromosomes undergoes meiosis. How many chromosomes are present in the cell after meiosis II? |
| | A) | 2 |
| | B) | 4 |
| | C) | 8 |
| | D) | 16 |
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5 | |
A diploid cell has 40 units of DNA at G1 of interphase. How many units of DNA are present in the cell after meiosis I? |
| | A) | 10 |
| | B) | 20 |
| | C) | 40 |
| | D) | 80 |
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6 | |
A diploid cell has 40 units of DNA at G1 of interphase. How many units of DNA are present in a gamete? |
| | A) | 10 |
| | B) | 20 |
| | C) | 40 |
| | D) | 80 |
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7 | |
The ____ is a membrane surrounding the embryo that gives rise to the umbilical blood vessels. |
| | A) | yolk sac |
| | B) | allantois |
| | C) | choronic villi |
| | D) | trophoblast |
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8 | |
The ____ is composed of specialized ectoderm that develops into the brain and spinal cord. |
| | A) | notochord |
| | B) | primitive streak |
| | C) | allantois |
| | D) | neural tube |
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9 | |
Chemicals or other agents that cause birth defects are called |
| | A) | transformers. |
| | B) | carcinogens. |
| | C) | alterations. |
| | D) | teratogens. |
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10 | |
The drug ____ was used to treat morning sickness between 1957 and 1961. Unfortunately, babies born to mothers who used this drug were born with incomplete or missing legs and arms. |
| | A) | lithium |
| | B) | diethylstilbestrol |
| | C) | penicillamine |
| | D) | thalidomide |
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11 | |
A phenotypically normal woman has a polar body biopsy. Upon examination, the polar body is found to carry a disease-causing recessive allele. The woman knows that the associated oocyte |
| | A) | carries the mutant allele. |
| | B) | carries the normal allele. |
| | C) | cannot support the development of an embryo. |
| | D) | no conclusions can be dawn about the oocyte. |
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12 | |
Which of the following genetic disorders is expressed in individuals after the prenatal period? |
| | A) | polydactyly |
| | B) | cystic fibrosis |
| | C) | Huntington disease |
| | D) | albinism |
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13 | |
Before birth, a female's oocytes are |
| | A) | not present. |
| | B) | arrested in prophase I of meiosis. |
| | C) | arrested in prophase II of meiosis. |
| | D) | arrested in prophase of mitosis. |
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14 | |
Meiosis II proceeds in a female's oocyte |
| | A) | prior to birth. |
| | B) | monthly after puberty. |
| | C) | upon ovulation. |
| | D) | upon fertilization. |
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15 | |
Male gametes originate in ____ within the ____. They pass through the ____ and ____ where they mature before exiting the body. |
| | A) | seminiferous tubules, ovaries, epididymis, fallopian tubes |
| | B) | vasa deferentia, seminiferous tubules, testes, penis |
| | C) | seminiferous tubules, testes, epididymis, vasa deferentia |
| | D) | epididymis, ovaries, vasa deferentia, testes |
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16 | |
Around day 6 or 7 of embryonic development, hCG is secreted by |
| | A) | the blastomere. |
| | B) | the morula. |
| | C) | trophoblast cells. |
| | D) | the sperm. |
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17 | |
How long after fertilization does the fetal period begin? |
| | A) | the first week |
| | B) | the eighth week |
| | C) | the first trimester |
| | D) | the second trimester |
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18 | |
Genetic variability arises during meiosis from |
| | A) | crossing over. |
| | B) | independent assortment. |
| | C) | random alignment of chromosomes at metaphase. |
| | D) | all of the above. |
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19 | |
Which of the following is a rapid-aging disorder? |
| | A) | porphyria |
| | B) | pattern baldness |
| | C) | progeria |
| | D) | Marfan syndrome |
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20 | |
Dolly, the sheep, was cloned from |
| | A) | an embryonic cell. |
| | B) | a fetal cell. |
| | C) | a mammary gland cell. |
| | D) | an artificial cell. |
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21 | |
Birth defects can result from a (an) ____ or ____. However, only the latter are transmitted to future generations. |
| | A) | environmental intervention, malfunctioning gene |
| | B) | malfunctioning gene, environmental intervention! |
| | C) | acquired characteristic, environmental intervention |
| | D) | malfunctioning gene, acquired characteristic |
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22 | |
How many sets of chromosomes are present in a primary oocyte and the polar body derived from it? |
| | A) | 2, 1 |
| | B) | 2, 2 |
| | C) | 1, 2 |
| | D) | 1, 1 |
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23 | |
Which of the following statements about gamete formation is false? |
| | A) | in females, most of the cytoplasm concentrates in one huge cell |
| | B) | in males, meiosis produces four similarly shaped sperm |
| | C) | spermatogenesis takes months |
| | D) | oogenesis is completed prior to birth |
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24 | |
____ is a failure of ____ to fully separate the digits. |
| | A) | Syndactyly, apoptosis |
| | B) | Polydactyly, apoptosis |
| | C) | Syndactyly, mitosis |
| | D) | Polydactyly, mitosis |
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25 | |
Are the sister chromatids of a chromosome necessarily identical at the beginning of metaphase I of meiosis? |
| | A) | yes, sister chromatids are always identical structures |
| | B) | yes, only homologous chromosomes differ from each other |
| | C) | no, crossing over could generate differences |
| | D) | maybe, it varies from cell division to cell division> |
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