Umbilical arteries:
A. deliver oxygen and nutrient-rich blood from the mother to the placenta.
B. deliver oxygen and nutrient-rich blood from the fetus to the placenta.
C. carry blood with low oxygen and high metabolic wastes away from the fetus to the placenta.
D. carry highly oxygenated blood from the placenta to the fetus.
E. carry blood with low oxygen and high metabolic wastes from the placenta to the mother's circulation.
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Question 2) Which of these results from the second meiotic division?
A. two diploid daughter cells with 46 chromosomes each
B. two haploid daughter cells with 23 chromosomes each
C. two diploid daughter cells with 23 chromosomes each
D. a single daughter cell with 46 chromosomes, and a polar body with no genetic material
E. two haploid daughter cells with 46 haploid chromosomes
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Question 3) Following crossing-over in meiosis I, which of the following is NOT true?
A. Maternal and paternal chromatids will always orient to opposite poles of the cell, remaining segregated from one another.
B. Random orientation of maternal and parental chromatids to either pole of the cell allows mixing of these in resultant gametes.
C. It is extremely unlikely that all 23 maternal and paternal chromosomes will end up in the same gamete.
D. A resulting gamete may have millions of possible different combinations of maternal and paternal chromosomes.
E. Chromatid pairs lined up in the cell are separated so that half end up in each daughter cell when division occurs.
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Question 4) Which of the following hormones is NOT secreted by the placenta during pregnancy?
A. human placental lactogen
B. androgens
C. estradiol
D. progesterone
E. inhibin
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Question 5) The major source of estradiol and progesterone in a non-pregnant woman is the:
A. thyroid gland.
B. adrenal gland.
C. testis.
D. ovary.
E. uterus.
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Question 6) During in utero (fetal) development of the ovary, which of these occurs?
A. Cell division of primary oogonia results in the production of 2 to 4 million primary oocytes, which are present at birth.
B. Cell division of primary oogonia, which all complete the first meiotic division before birth.
C. Cell division of primary oogonia, which all complete both meiotic divisions before birth.
D. The mitotic division of primary and secondary oocytes produces cells with 23 chromosomes each.
E. A single primary oogonium remains dormant, which then undergoes rapid mitosis after birth.
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Question 7) Menopause:
A. is the cessation of menstrual cycles.
B. results in high plasma levels of estrogens.
C. occurs as a result of cessation of gonadotropin secretion.
D. is the cessation of ovulation while a baby is nursing.
E. is the pause in development of ovarian follicles occurring between the birth of a baby girl and when she reaches puberty.
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Question 8) Lactation normally does not occur during pregnancy because
A. the breast ducts do not develop until after a baby is born.
B. the high levels of estrogen and progesterone in maternal plasma inhibit prolactin effects on the breasts.
C. maternal plasma levels of prolactin are low during pregnancy.
D. high levels of androgens inhibit milk synthesis by the breasts.
E. the low levels of circulating estrogen and progesterone during pregnancy inhibit milk synthesis by the breasts.
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Question 9) Which is LEAST important for supporting continuing lactation after a baby is born?
A. the suckling stimulus
B. emptying milk from the breast
C. the secretion of oxytocin
D. the secretion of prolactin
E. high levels of estrogen and progesterone
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Question 10) Which of the following statement is FALSE regarding oxytocin?
A. It is secreted by the posterior pituitary.
B. It is synthesized by the hypothalamus and promotes contraction of myoepithelial cells in the breasts.
C. It facilitates the birth process.
D. It stimulates uterine contractions.
E. It stimulates synthesis of breast milk.
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