Deck 17: Reproduction

Question 1

In the differentiation of a normal female,

A)Müllerian inhibiting substance causes the Müllerian ducts to regress
B)The uterus and uterine 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)None of the choices are true

Answer 1

C

Question 2

Sertoli cells

A)Form a barrier between the blood and developing germ cells
B)Secrete inhibin
C)Protect spermatagonia from chemicals in the blood that might damage them
D)Both form a barrier between the blood and developing germ cells and secrete inhibin are correct
E)All of the choices are correct

Answer 2

D

Question 3

Spermatogenesis

A)Begins with the mitotic division of a single spermatogonium
B)Results in four primary spermatocytes for every spermatogonium
C)Results in four spermatozoa for every primary spermatocyte
D)Both begins with the mitotic division of a single spermatogonium and results in four spermatozoa for every primary spermatocyte are correct
E)All of the choices are correct

Answer 3

D

Question 4

Meiosis

A)Differs from mitosis in that in meiosis cell division occurs without chromosome replication
B)Differs from mitosis in that in meiosis two cell divisions follow one chromosomal replication
C)Allows for mixing of paternal and maternal genes on homologous chromosomes
D)Both differs from mitosis in that in meiosis cell division occurs without chromosome replication and allows for mixing of paternal and maternal genes on homologous chromosomes are correct
E)Both differs from mitosis in that in meiosis two cell divisions follow one chromosomal replication and allows for mixing of paternal and maternal genes on homologous chromosomes are correct

Question 5

Which of the following statements is false?

A)Sperm formed in the testes enter the epididymis before entering the vas deferens
B)The seminal fluid is alkaline and rich in nutrients
C)The Sertoli cells produce androgen-binding protein
D)Sperm entering the epididymis are fully motile
E)Most of the seminal volume is provided by the secretions of the seminal vesicles and prostate gland

Question 6

Which of the following would be likely to occur in an adult male whose Sertoli cells have begun to produce excessive amounts of inhibin?

A)FSH secretion would be selectively inhibited, but LH secretion would be normal
B)Spermatogenesis would be depressed but testosterone secretion would be normal
C)Spermatogenesis would be enhanced because of the elevated production of testosterone
D)Both FSH secretion would be selectively inhibited, but LH secretion would be normal and spermatogenesis would be depressed but testosterone secretion would be normal are correct
E)Both FSH secretion would be selectively inhibited, but LH secretion would be normal and spermatogenesis would be enhanced because of the elevated production of testosterone are correct

Question 7

Sexual differentiation of the embryo is normally determined by

A)The presence of two X chromosomes, which directs the undifferentiated gonads to develop into ovaries
B)The presence of the Y chromosome, which directs the undifferentiated gonads to develop into testes (when there is one X chromosome present as well)
C)Hormones produced by the placenta
D)Both the presence of two X chromosomes, which directs the undifferentiated gonads to develop into ovaries and hormones produced by the placenta
E)Both the presence of the Y chromosome, which directs the undifferentiated gonads to develop into testes (when there is one X chromosome present as well) and hormones produced by the placenta

Question 8

Sperm

A)Are stored in the vas deferens and the last part of the epididymis
B)Mature in the vas deferens
C)Become concentrated in the epididymis
D)Both are stored in the vas deferens and the last part of the epididymis and become concentrated in the epididymis are correct
E)All of the choices are correct

Question 9

SRY

A)Protein is normally coded for by a gene that is present on the Y chromosome
B)Protein is normally coded for by a gene that is present on the X chromosome
C)Gene codes for testosterone
D)Gene is indirectly involved in differentiation of the indifferent gonad and directly involved in the regression of the Müllerian ducts
E)Both protein is normally coded for by a gene that is present on the Y chromosome and gene is indirectly involved in differentiation of the indifferent gonad and directly involved in the regression of the Müllerian ducts are correct

Question 10

In the differentiation of a normal male,

A)Undifferentiated gonads develop into testes during the fifth week of embryonic life
B)The Wolffian ducts regress
C)Pituitary LH causes fetal Leydig cells to secrete testosterone
D)Testosterone directly stimulates development of the epididymis, vas deferens, and seminal vesicles
E)Testosterone directly stimulates development of the penis and scrotum

Question 11

As sperm travel from their site of production in the testes to the exterior,the sequence of ducts through which they will pass is:

A)Rete testis; efferent ductules; epididymis; vas deferens; ejaculatory duct; prostatic urethra; penile urethra
B)Efferent ductules; rete testis; epididymis; vas deferens; ejaculatory duct; prostatic urethra; penile urethra
C)Rete testis; efferent ductules; epididymis; vas deferens; prostatic urethra; ejaculatory duct; penile urethra
D)Rete testis; afferent ductules; epididymis; vas deferens; ejaculatory duct; prostatic urethra; penile urethra
E)Rete testis; efferent ductules; epididymis; vas deferens; prostatic urethra; penile urethra; ejaculatory duct

Question 12

The uterine tubes

A)Are also called fallopian tubes
B)Are also called oviducts
C)Connect the uterus to the ovaries
D)Both are also called fallopian tubes and are also called oviducts are correct
E)All of the choices are correct

Question 13

Which of the following best describes the reproductive organs of a genetic male who lacks androgen receptors (i.e.,has androgen insensitivity)?

A)He will have normal male genitals and sex accessory organs
B)He will have female-appearing genitals and sex accessory organs
C)He will have female-appearing external genitals but normal male sex accessory organs derived from the Wolffian ducts
D)He will have male genitals but will have female-appearing sex accessory organs derived from the Müllerian ducts
E)He will have female-appearing external genitals but no internal sex accessory organs derived from the duct structures

Question 14

Ejaculation is accompanied by dilation of the pupils.This pupillary dilation

A)Occurs because ejaculation is triggered by a parasympathetic reflex
B)Occurs because ejaculation is triggered by a sympathetic reflex
C)Is a coincidence unrelated to reflexes
D)Is a consequence of prior intense physical exertion
E)Is a myth

Question 15

A female whose adrenal glands began secreting unusually high levels of androgen would probably have increased

A)Subcutaneous fat deposition
B)Growth of facial hair
C)Development of skeletal muscle strength
D)Subcutaneous fat deposition and growth of facial hair
E)Growth of facial hair and development of skeletal muscle strength

Question 16

The process of spermatogenesis from primary spermatocyte to sperm

A)Takes about three weeks in the human
B)Takes place in an environment different from that of the mitotic cell divisions that precede it
C)Requires participation of Sertoli cells
D)Both takes about three weeks in the human and takes place in an environment different from that of the mitotic cell divisions that precede it are correct
E)Both takes place in an environment different from that of the mitotic cell divisions that precede it and requires participation of Sertoli cells are correct

Question 17

Which of the following is not true regarding erection of the penis?

A)It is a spinal reflex
B)It is a result of sympathetic stimulation of vascular smooth muscle in the erectile tissue of the penis
C)It can be triggered by stimulation of tactile receptors in the penis
D)It is a result of arteriolar vasodilation and venous constriction of blood vessels in the penis
E)It can be inhibited by input to the autonomic nerves from higher brain centers

Question 18

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 gonads to pituitary gonadotropins and sensitivity of the pituitary to GnRH
E)All of the choices are correct

Question 19

Which of the following statements about the male sex accessory organs is true?

A)The prostate gland secretes prostaglandins
B)The seminal vesicles secrete prostaglandins
C)The bulbourethral glands secrete mucus
D)Both the prostate gland secretes prostaglandins and the bulbourethral glands secrete mucus are true
E)Both the seminal vesicles secrete prostaglandins and the bulbourethral glands secrete mucus are true

Question 20

The androgen-binding protein functions to

A)Confer responsiveness of certain cells to male sex hormones
B)Transport androgens in the plasma
C)Bind and maintain high concentrations of testosterone in the seminiferous tubules
D)Both confer responsiveness of certain cells to male sex hormones and transport androgens in the plasma
E)Do all of these things

Question 21

Estradiol is proconception because it

A)Stimulates follicle and oocyte maturation and promotes ovulation
B)Changes cervical mucus to make it penetrable by sperm
C)Increases libido, or sex drive, in women
D)Both stimulates follicle and oocyte maturation and promotes ovulation and changes cervical mucus to make it penetrable by sperm are correct
E)Does all of these things

Question 22

During the early part of the menstrual cycle,________ acts on granulosa cells,which ________.________ acts on theca cells,which ________.

A)LH; convert androgens to estrogens; FSH; synthesize androgens
B)LH; synthesize androgens; FSH; convert androgens to estrogens
C)FSH; convert androgens to estrogens; LH; synthesize androgens
D)FSH; synthesize androgens; LH; convert androgens to estrogens
E)Progesterone; synthesize androgens; LH; secrete estrogens

Question 23

On day 14 of a typical 28 day menstrual cycle,LH levels will be ________.The endometrium will be ________.Estrogen levels in the blood are ________.

A)Level; sloughing off; low
B)At or near a peak; near the end of the proliferative phase; relatively high
C)Low but rising; in the secretory phase; high
D)At or near a peak; in the secretory phase; low
E)Level; starting the proliferative phase; level but high

Question 24

Shedding of the endometrial lining occurs

A)Because the corpus luteum of that cycle is regressing
B)As a result of a fall in plasma levels of estradiol and progesterone
C)Soon after the LH surge
D)Both because the corpus luteum of that cycle is regressing and as a result of a fall in plasma levels of estradiol and progesterone are correct
E)All of the choices are correct

Question 25

The follicular phase of the ovarian cycle coincides with which phase or phases of the uterine cycle?

A)The menstrual phase
B)The proliferative phase
C)The secretory phase
D)The last half of the proliferative and the first half of the secretory phases
E)Both the menstrual phase and the proliferative phase are correct

Question 26

The maturation of ovarian follicles

A)Promotes the maturation of the oocyte so that it can be fertilized after ovulation
B)Results in the secretion of estrogen, which stimulates the LH surge that in turn causes ovulation
C)Culminates with the second meiotic division of the egg
D)Both promotes the maturation of the oocyte so that it can be fertilized after ovulation and results in the secretion of estrogen, which stimulates the LH surge that in turn causes ovulation are correct
E)All of the choices are correct

Question 27

The dominant follicle

A)Undergoes atresia
B)Continues to develop after other antral follicles have begun to degenerate
C)Undergoes ovulation
D)Both undergoes atresia and undergoes ovulation are correct
E)Both continues to develop after other antral follicles have begun to degenerate and undergoes ovulation are correct

Question 28

LH

A)Stimulates androgen production by theca cells
B)Is required for estrogen secretion by granulosa cells
C)Secretion during the latter part of the follicular phase is decreased by inhibin secreted by granulosa cells
D)Both stimulates androgen production by theca cells and is required for estrogen secretion by granulosa cells are correct
E)All of the choices are correct

Question 29

At ovulation,

A)The follicle ruptures
B)The second meiotic division of the oocyte occurs
C)The oocyte, along with its surrounding thecal layer, is expelled onto the ovarian surface
D)The follicle ruptures and the second meiotic division of the oocyte occurs
E)All of the choices occur

Question 30

Effects of the LH surge on the mature follicle include

A)Stimulation of estrogen secretion
B)Stimulation of prostaglandin secretion
C)Luteinization of the unovulated granulosa cells
D)Stimulation of estrogen secretion and stimulation of prostaglandin secretion
E)Stimulation of prostaglandin secretion and luteinization of the unovulated granulosa cells

Question 31

The secretory phase of the menstrual cycle

A)Corresponds to the luteal phase of the ovarian cycle
B)Refers to the endocrine function of the endometrium
C)Requires both estrogen and progesterone
D)Both corresponds to the luteal phase of the ovarian cycle and refers to the endocrine function of the endometrium are correct
E)Both corresponds to the luteal phase of the ovarian cycle and requires both estrogen and progesterone are correct

Question 32

Beginning on the first day of the menstrual cycle,the order of events in the uterus is

A)Proliferative, secretory, menstrual phases
B)Secretory, proliferative, menstrual phases
C)Menstrual, secretory, proliferative phases
D)Menstrual, proliferative, secretory phases
E)Secretory, menstrual, proliferative phases

Question 33

Which of the following organs can produce androgens?

A)Testes
B)Ovaries
C)Adrenal cortices
D)Both testes and ovaries are correct
E)All of the choices are correct

Question 34

The transition between the (X)________ and the (Y)________ phases of the uterine cycle coincides with ________.The (X)phase is terminated by ________ in the plasma concentration of ________ and ________ in the concentration of ________.

A)Follicular; luteal; a rise in basal body temperature; a decrease; estrogen and progesterone; a decrease; inhibin
B)Proliferative; secretory; ovulation; a decrease; estrogen; an increase; progesterone
C)Menstrual; proliferative; the onset of follicular growth; an increase; estrogen; a decrease; progesterone
D)Secretory; proliferative; the LH surge; a decrease; FSH; an increase; estrogen and progesterone
E)Proliferative; secretory; the LH surge; an increase; inhibin; a decrease; estrogen and progesterone

Question 35

Which of the following statements about estrogen is not true?

A)In low plasma concentration, estrogen inhibits pituitary secretion of LH and FSH
B)In high plasma concentration, estrogen stimulates pituitary sensitivity to GnRH
C)In the presence of high plasma concentration of progesterone, estrogen stimulates increased secretion of GnRH
D)Estrogen secretion is required for the LH surge
E)Estrogen stimulates follicular growth

Question 36

Menstrual cycles

A)Refer only to events occurring in the uterus
B)Are caused by changes in hormone levels
C)In normal women repeat every 28 days
D)Both refer only to events occurring in the uterus and are caused by changes in hormone levels are correct
E)All of the choices are correct

Question 37

On day 1 of the menstrual cycle,FSH levels will be ________.The follicle that will become dominant is in the ________ stage of maturation.Progesterone levels in blood are ________.

A)Rising; primordial; low
B)Rising; preantral to antral; low
C)Rising; preantral to antral; high
D)Falling; expanding; low
E)Falling; atretic; high

Question 38

If you start at the plasma membrane of an oocyte in a mature follicle and move outward,which is the correct order in which you would encounter the three structures listed below?

A)Zona pellucida; granulosa cells; theca cells
B)Zona pellucida; theca cells; granulosa cells
C)Granulosa cells; zona pellucida; theca cells
D)Granulosa cells; theca cells; zona pellucida
E)Theca cells; zona pellucida; granulosa cells

Question 39

Which of the following is not an action of estrogen?

A)Stimulation of fat deposition under the skin in the breasts and hips
B)Vaginal cornification
C)Stimulation of myometrial contractions
D)Stimulation of bone growth and strength
E)Stimulation of growth of pubic hair

Question 40

According to the two-cell mechanism of follicular estrogen synthesis,

A)Granulosa cells synthesize an androgen which the theca cells convert to estrogen
B)Sertoli cells synthesize an androgen which the granulosa cells convert to dihydrotestosterone
C)The ca cells synthesize an androgen which luteal cells convert to estrogen
D)Production of progesterone by the corpus luteum requires cooperative interaction between two cell types
E)Theca cells synthesize an androgen which the granulosa cells convert to estrogen

Question 41

The actions of progesterone

A)On the female reproductive tract are often antagonistic to those of estrogen
B)Are limited to the female reproductive tract and breasts
C)Are mediated through plasma membrane receptors
D)Both on the female reproductive tract are often antagonistic to those of estrogen and are limited to the female reproductive tract and breasts are correct
E)Both on the female reproductive tract are often antagonistic to those of estrogen and are mediated through plasma membrane receptors are correct

Question 42

Regarding transport of sperm in the female reproductive tract,

A)Most of the ejaculated sperm arrive in the vicinity of the ovum (if there is one)
B)Sperm transport through the cervix is made possible by actions of progesterone on the cervical mucus
C)During this transport sperm acquire the ability to fertilize an ovum
D)Both most of the ejaculated sperm arrive in the vicinity of the ovum (if there is one) and sperm transport through the cervix is made possible by actions of progesterone on the cervical mucus are correct
E)Both sperm transport through the cervix is made possible by actions of progesterone on the cervical mucus and during this transport sperm acquire the ability to fertilize an ovum are correct

Question 43

The blastocyst implants in the uterus on about the ________ day of the 28 day menstrual cycle.At this time,the endometrium is ________ and progesterone levels are _______.

A)21st; thick and secretory; high
B)28th; thick and secretory; low
C)14th; thick and secretory; low
D)7th; thin and proliferating; high
E)1st; thin and proliferating; low

Question 44

Lactation normally does not occur during pregnancy because

A)The breasts are not fully developed until the end of pregnancy
B)The high levels of estrogen and progesterone in maternal plasma inhibit milk synthesis by the breasts
C)Maternal plasma levels of prolactin are low during pregnancy
D)Both the breasts are not fully developed until the end of pregnancy and the high levels of estrogen and progesterone in maternal plasma inhibit milk synthesis by the breasts are correct
E)Both the high levels of estrogen and progesterone in maternal plasma inhibit milk synthesis by the breasts and maternal plasma levels of prolactin are low during pregnancy are correct

Question 45

Which of the following statements regarding breast growth is correct?

A)During puberty, ductal growth is stimulated by rising estrogen levels in plasma
B)Some alveolar growth occurs after ovulatory cycles start because of the combined actions of estrogen, progesterone, and prolactin
C)During pregnancy, full lobulo-alveolar growth is stimulated by the combined actions of estrogen, progesterone, and placental gonadotropin
D)Both during puberty, ductal growth is stimulated by rising estrogen levels in plasma and some alveolar growth occurs after ovulatory cycles start because of the combined actions of estrogen, progesterone, and prolactin are correct
E)All of the choices are correct

Question 46

Which of the following statements is true?

A)The mother and the fetus exchange nutrients by exchanging blood in the placenta
B)Chorionic gonadotropin maintains the corpus luteum
C)Chorionic gonadotropin levels are the highest at the end of pregnancy
D)From the time of implantation through delivery, the corpus luteum is the major source of progesterone
E)All of the choices are true

Question 47

Normal physiological consequences of pregnancy to the mother include

A)Increased appetite
B)Increased blood volume
C)Increased blood pressure
D)Increased appetite and increased blood volume
E)All of the choices

Question 48

Regarding transport of the egg,

A)During ovulation the secondary oocyte is ejected from the ovary directly into the uterine tube
B)Movement of the oocyte into the uterine tube is facilitated by cilia beating toward the ovary
C)Movement of the oocyte into the uterine tube is facilitated by cilia beating toward the uterus
D)Both during ovulation the secondary oocyte is ejected from the ovary directly into the uterine tube and movement of the oocyte into the uterine tube is facilitated by cilia beating toward the ovary are correct
E)Both during ovulation the secondary oocyte is ejected from the ovary directly into the uterine tube and movement of the oocyte into the uterine tube is facilitated by cilia beating toward the uterus are correct

Question 49

During pregnancy,an important role of progesterone is to inhibit

A)The sensitivity of the myometrium to stimuli that promote contraction
B)Penetration of the uterus by producing thickened cervical mucus
C)Growth of the mammary glands
D)Both the sensitivity of the myometrium to stimuli that promote contraction and penetration of the uterus by producing thickened cervical mucus
E)All of these things

Question 50

Implantation

A)Outside the uterus is said to be myopic
B)Normally occurs midway through the luteal phase
C)Is a result of digestion of myometrial cells by enzymes in the trophoblast
D)Both outside the uterus is said to be myopic and normally occurs midway through the luteal phase are correct
E)Both normally occurs midway through the luteal phase and is a result of digestion of myometrial cells by enzymes in the trophoblast are correct

Question 51

At the time of birth,the mother's breast is filled with a fluid that

A)Is called colostrum
B)Has a high concentration of immune globulins and other proteins
C)Has the same composition as the milk that is produced throughout lactation
D)Both is called colostrum and has a high concentration of immune globulins and other proteins are correct
E)Both has a high concentration of immune globulins and other proteins and has the same composition as the milk that is produced throughout lactation are correct

Question 52

During pregnancy,placental lactogen serves to

A)Inhibit glucose utilization by maternal tissues
B)Promote breast growth
C)Increase maternal metabolism of fatty acids
D)Inhibit glucose utilization by maternal tissues and promote breast growth
E)Do all of these things

Question 53

Normally,only one sperm can fertilize an egg because

A)The first sperm to fuse with the oocyte plasma membrane triggers a process whereby enzymes begin to inactivate other nearby sperm
B)The first sperm to fuse with the oocyte plasma membrane triggers a process whereby the zona pellucida becomes impenetrable to other sperm
C)Only one sperm normally makes it to the vicinity of the egg
D)Only one sperm undergoes the acrosome reaction
E)Only one sperm undergoes capacitation

Question 54

The implanting blastocyst "rescues" the corpus luteum by secreting

A)Large quantities of FSH and LH
B)GnRH, which stimulates the pituitary gland to secrete FSH and LH
C)Chorionic gonadotropin
D)Progesterone and estrogen
E)All of these things

Question 55

Which of the following statements regarding the control of parturition is not true?

A)Oxytocin secretion is stimulated by cervical dilation
B)Coordinated uterine contractions cause the cervix to dilate
C)Oxytocin increases myometrial estrogen receptors
D)Prostaglandins stimulate myometrial contractions
E)Stretching of the myometrium is one signal that begins uterine contractions

Question 56

Parturition

A)Refers to delivery of the infant and placenta
B)Normally occurs between the 27th and 28th weeks of pregnancy
C)Is an example of positive feedback
D)Includes refers to delivery of the infant and placenta and is an example of positive feedback
E)All of the choices are correct

Question 57

During pregnancy,the

A)Corpus luteum must remain functional for 38 weeks
B)Placenta secretes steroid and peptide hormones
C)Placenta requires precursors from the fetal adrenal cortex for estrogen synthesis
D)Both corpus luteum must remain functional for 38 weeks and placenta requires precursors from the fetal adrenal cortex for estrogen synthesis are correct
E)Both placenta secretes steroid and peptide hormones and placenta requires precursors from the fetal adrenal cortex for estrogen synthesis are correct

Question 58

The placenta

A)Is an organ of nourishment for the embryo/fetus
B)Functions as the lungs and kidneys of the fetus prior to birth
C)Allows for mixing of fetal and maternal blood
D)Both is an organ of nourishment for the embryo/fetus and functions as the lungs and kidneys of the fetus prior to birth are correct
E)All of the choices are correct

Question 59

Functions of estrogen during pregnancy include each of the following except

A)Stimulation of myometrial growth
B)Maintenance of the endometrium
C)Stimulation of prolactin secretion
D)Stimulation of breast development
E)Stimulation of milk synthesis

Question 60

At the end of pregnancy,the uterus becomes responsive to stimuli to which it was previously refractory because

A)Plasma progesterone levels fall while the levels of estrogen continue to rise
B)The ratio of progesterone to estrogen decreases
C)The myometrium has reached the limits of its distensibility
D)All of the choices are correct
E)None of the choices are correct

Question 61

Prostaglandins were given their name because they are secreted in high concentration into semen by the prostate gland.

Question 62

During in utero (fetal)development of the ovary

A)Cell division of primary oogonia stops at 7 months following conception
B)Cell division of primary oogonia begins and does not cease until menopause begins, long after birth at age 40-50
C)Production of primary oocytes is initiated and continues to the point of producing fully functional ova (egg cells) at the time of birth
D)The mitotic division of primary and secondary oocytes produces cells with 23 chromosomes each
E)All of the choices are correct

Question 63

Meiosis results in germ cells with 23 maternal chromosomes in one daughter cell and 23 paternal chromosomes in the other.

Question 64

The products of the first meiotic division of spermatogenesis are spermatids.

Question 65

The source of the estrogens; estradiol and progesterone is the

A)Thyroid gland
B)Adrenal gland
C)Testis
D)Ovary
E)Uterus

Question 66

Umbilical arteries

A)Provide the means for distribution of oxygen and nutrients between maternal and fetal blood
B)Deliver oxygen and nutrient rich blood from the fetus to the placenta
C)Direct blood with low oxygen and high metabolic wastes away from the fetus to the placenta
D)Carry highly oxygenated blood to the fetus
E)Transport poorly oxygenated blood low rich in nutrients toward the fetal heart

Question 67

Lactation is maintained by

A)The suckling stimulus
B)Removal of milk from the breast
C)The secretion of oxytocin
D)The secretion of prolactin
E)All of these choices

Question 68

To promote pregnancy,sexual intercourse must introduce spermatozoa into the vagina no more than ______ days before ovulation,and no more than ______ days after ovulation.

A)0, 3
B)1, 1
C)2, 3
D)2, 4
E)5, 1

Question 69

Menopause

A)Is the cessation of menstrual cycles
B)Results in low plasma levels of estrogens
C)Occurs as a result of cessation of gonadotropin secretion
D)Both is the cessation of menstrual cycles and results in low plasma levels of estrogens are correct
E)All of the choices are correct

Question 70

The testes are located outside the abdomen because spermatogenesis requires a temperature lower than core body temperature.

Question 71

One way in which gametogenesis in males differs from gametogenesis in females is that mitosis of primordial germ cells occurs in males only during fetal life.

Question 72

Conversion of spermatids to spermatozoa involves cell division.

Question 73

Which of the following hormones is formed by the placenta during pregnancy?

A)Aromatase
B)Estradiol
C)Estrone
D)Progestin
E)Andromin

Question 74

Oxytocin is a hormone that

A)Is secreted by the posterior pituitary and stimulates uterine contractions
B)Is synthesized by the hypothalamus and promotes contraction of myoepithelial cells
C)Facilitates the birth process
D)Both is secreted by the posterior pituitary and stimulates uterine contractions and is synthesized by the hypothalamus and promotes contraction of myoepithelial cells are correct
E)Does all of these things

Question 75

The retention of a developing embryo from a zygote and implantation in the wall of the uterine tube creates an extreme risk of rupture,hemorrhage,and spontaneous abortion and is called a(n)_______.

A)Stillbirth
B)Erythroblastosis fetalis
C)Ectopic pregnancy
D)Endometriosis
E)Placenta previa

Question 76

Following crossing-over in Meiosis I - all of the following are true,except:

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 that all 23 maternal and paternal chromosomes will end up in the same gamete
D)A resulting gamete may have over eight million possible different combinations of maternal and paternal chromosomes
E)It is possible for one gamete to carry only maternal chromosomes or paternal chromosomes

Question 77

Implantation of the blastocyst

A)Occurs within the uterine (fallopian) tube
B)Takes place during days 14-21 of the typical menstrual cycle
C)Is dependent upon the proper preparation of the endometrial epithelium of the uterus
D)Takes place only if levels of progesterone in the blood have risen to the point of relaxing smooth muscle in the uterus
E)Both takes place during days 14-21 of the typical menstrual cycle and is dependent upon the proper preparation of the endometrial epithelium of the uterus are correct

Question 78

In the testis,spermatogenesis takes place in the seminiferous tubules and testosterone is produced by the Leydig cells.

Question 79

In the second part of meiosis - Meiosis II

A)Replicated DNA undergoes additional genetic recombination
B)The final product is two haploid daughter cells with 23 chromosomes each
C)Additional recombinations occur, producing an even higher number of different paternal and maternal chromosomal combinations
D)Both replicated DNA undergoes additional genetic recombination and the final product is two haploid daughter cells with 23 chromosomes each are correct
E)Both the final product is two haploid daughter cells with 23 chromosomes each and additional recombinations occur, producing an even higher number of different paternal and maternal chromosomal combinations are correct

Question 80

The part of the spermatozoan that enables it to swim through fluid is the acrosome.