In the embryonic differentiation of a normal male:
A. undifferentiated gonads develop into testes during the fifth week of embryonic life.
B. the Wolffian ducts regress.
C. Mullerian inhibiting substance is absent.
D. testosterone directly stimulates development of the epididymis, vas deferens, and seminal vesicles.
E. testosterone directly stimulates development of the penis and scrotum.
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Question 2) Spermatogenesis:
A. begins with the mitotic division of spermatogonia.
B. results in four primary spermatocytes for every spermatogonium.
C. results in four spermatozoa for every primary spermatocyte.
D. is not complete until after an egg is fertilized, which initiates the second meiotic division.
E. takes place completely within the lumen of the seminiferous tubule.
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Question 3) Which of the following best describes a genetic male (XY) who lacks functional androgen receptors (androgen insensitivity syndrome)?
A. He will have normal male external genitalia.
B. He will have ovaries and female-appearing external genitalia but male secondary sex characteristics.
C. He will have female-appearing external genitalia and ovaries, but internal structures derived from the Wolffian ducts.
D. He will have male external genitalia but will have female-appearing internal structures derived from the Mllerian ducts.
E. He will have undescended testes, but female external genitalia and secondary sex characteristics.
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Question 4) The onset of puberty is triggered by an increase in:
A. sensitivity of the gonads to pituitary gonadotropins.
B. sensitivity of the pituitary to GnRH.
C. GnRH secretion.
D. sensitivity of the hypothalamus to negative feedback by sex steroids.
E. sensitivity of the pituitary to negative feedback by sex steroids.
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Question 5) Which is TRUE regarding meiosis in a single germ cell?
A. It results in 2 cells with 46 chromosomes each.
B. It results in 4 cells with 23 chromosomes each.
C. It results in 4 cells with 23 pairs of chromosomes each.
D. It results in 4 cells with 46 chromosomes each.
E. It results in 4 cells with 46 pairs of chromosomes each.
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Question 6) In the differentiation of a normal female:
A. Mllerian inhibiting substance causes the Mllerian ducts to regress.
B. the uterus and fallopian tubes are formed from the Wolffian ducts.
C. female genitalia form in the absence of hormonal stimulation.
D. the gonads remain undifferentiated throughout fetal life.
E. the SRX protein present on X chromosomes makes the gonads differentiate into ovaries.
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Question 7) With regard to reproduction, which is correct about SRY?
A. It is a protein that is normally coded for by a gene that is present on the Y chromosome.
B. It is a gene that codes for testosterone.
C. It is a protein that causes the degeneration of the Wolffian ducts.
D. It is a gene found in both males and females.
E. It is a protein normally coded for by a gene that is present on the X chromosome.
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Question 8) Sexual differentiation of the embryo is normally determined by:
A. the number of chromosomes, with males having 22 pairs and females having an extra pair of XX chromosomes.
B. the presence of two X chromosomes, which causes the primordial testes to degrade.
C. the presence of one Y chromosome, which causes the primordial ovaries to degrade.
D. the presence of the Y chromosome, which directs the undifferentiated gonads to develop into testes (when there is one X chromosome present as well).
E. hormones produced by the placenta.
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Question 9) Heat loss from evaporation occurs only when one is sweating.
Indicate whether the statement is true or false.
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Question 10) The reason high humidity plays such a significant role in increasing the discomfort felt on very hot days is that it decreases the cooling properties of conduction.
Indicate whether the statement is true or false.
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