Practice Questions Flashcards by Cari Nicholas

The part of the sperm containing
proteolytic enzymes to digest the zona
pellucida is the:
A. capacitor
B. head
C. corona
D. acrosome
E. cumulus

D. is correct.
The acrosome is the part of the sperm containing
proteolytic enzymes to digest the zona pellucida. It is
exposed by the process of capacitation. Then, under the
influence of substances released by corona radiata cells,
it releases its proteolytic enzymes and penetrates the
oocyte.

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The ovulated mammalian oocyte is
arrested at:
A. prophase of meiosis I
B. metaphase of meiosis I
C. prophase of meiosis II
D. metaphase of meiosis II
E. none of the above

D. is correct.
The long arrest in meiosis occurs in the primary oocyte.
These descendants of oogonia begin meiosis before birth
and stop dividing during prophase of the first division.
Years later, this first division is completed just prior to
ovulation. Ovulated secondary oocytes then stop at
metaphase II until fertilized.

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The seven-day blastocyst:
A. has a single layer of trophoblast at the embryonic pole
B. has an amniotic cavity
C. is attached to the endometrial epithelium
D. is surrounded by a degenerating zona pellucida
E. is called the hypoblast

C. is correct.
The decidual reaction of the endometrium creates a nourishing environment for the conceptus a it buries itself by invasion of the uterine endometrial wall. Progesterone produced by the corpus luteum stimulates glandular secretion in the endometrium during the secretory phase of menstruation or early pregnancy.

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Haploid nuclei that fuse at fertilization are called:
A. homunculi
B. mitotic figures
C. centrioles
D. nucleoli
E. pronuclei

E. is correct. After the sperm reaches the ovum, it deposits its genetic load, the male pronucleus, into the cytoplasm of the egg. After finally completing the meiotic division that had begun years before, the female pronucleus fuses with the male pronucleus to create the diploid nucleus of the zygote

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The first week of human development is characterized by formation of the:
A. inner cell mass
B. hypoblast
C. trophoblast
D. blastocyst
E. all of the above

E. is correct. At four days, the blastocyst cavity of blastocoel forms within the morula. Trophoblast are outer cells of the blastocyst, while a knot of cells appears, protruding into the blastocele. This is the inner cell mass. Trophoblast becomes 2 layers: syncytiotrophoblast and cytotrophoblast. Inner cell mass becomes epiblast and hypoblast.

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During implantation, the blastocyst:
A. implants in the endometrium
B. usually attaches to endometrial epithelium at its embryonic pole
C. usually implants in the posterior wall of the body of the uterus
D. causes change in the endometrial tissues
E. all of the above are correct

E. is correct. Implantation occurs when the trophoblast cells at the embryonic pole secrete proteolytic enzymes that allow the blastocyst to penetrate the wall of the uterus, usually the posterior wall. The endometrial lining responds to implantation through the decidua reaction, by which it becomes more succulent for nourishing the blastocyst.

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Capacitation of the sperm:
A. is caused by the zona pellucida
B. occurs in the male
C. prevents polyspermy
D. is essential for fertilization
E. removes the head of the sperm

D. is correct. Capacitation involves removing the glycoprotein coat and seminal plasma proteins from the head of the sperm, exposing the acrosome and allowing the acrosome reaction to occur. Capacitation occurs within the female genital tract, and without its occurrence, fertilization could not occur.

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The early stages of cleavage are characterized by:
A. formation of a hollow ball of cells
B. formation of the zona pellucida
C. increase in the size of the cells in the zygote
D. increase in the number of cells in the zygote
E. none of the above

D. is correct. The earliest stages of cleavage are marked by a series of mitotic divisions that increase the number of cells in the zygote without an increase in size. As the cleavage continues the zygote becomes a morula or a solid ball of 12-16 cells. A cavity forming within the morula transforms it into a blastocyst, at about day 4.

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The most common site for implantation in ectopic pregnancy is:
A. internal os of the uterus
B. mesentery
C. ovary
D. uterine tube
E. other

D. is correct. The most common site of ectopic implantation is the uterine tube. The growth of the embryo in this site usually causes rupture of the tube and severe hemorrhage in the mother. Abdominally, an ectopic pregnancy often occurs in the rectouterine pouch, an area between the uterus and the rectum.

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With the light microscope, the zona pellucida appears as a translucent membrane surrounding the:
A. primary oocyte
B. zygote
C. morula
D. very early blastocyst
E. all of the above are correct

E. is correct. The zona pellucida persists until early it the blastocyst stage. It dissolves during the blastocyst stage in order that implantation may occur.

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1.
Which of the following types of germ cells does not undergo cell division?
A. spermatogonia
B. primary oocytes
C. spermatids
D. secondary oocytes
E. oogonia

C. spermatids

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2.
Oogonia are homologous to spermatogonia. Oogonia divide by mitosis during:
A. all postnatal periods
B. fetal life
C. postnatal periods after puberty
D. the reproductive period
E. none of the above

B. fetal life

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3.
Prior to ejaculation, sperm are stored in the:
seminal vesicles
A. efferent ductules
B. epididymis
C. ejaculatory ducts
D. seminal colliculus

B. epididymis

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4.
How many sperms, approximately, are deposited in the vagina during intercourse?
A. 300 thousand
B. 3 million
C. 30 million
D. all of the above
E. none of the above

C. 30 million

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5.
The first meiotic division of the primary oocytes is characterized by:
A. pairing of homologous chromosomes
B. DNA replication
C. crossing over
D. production of a polar body
E. all of the above

E. all of the above

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6.
The part of the sperm containing proteolytic enzymes to digest the zona pellucida is the:
A. capacitor
B. head
C. corona
D. acrosome
E. cumulus

D. acrosome

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7.
The ovulated mammalian oocyte is arrested at:
A. prophase of meiosis I
B. metaphase of meiosis I
C. prophase of meiosis II
D. metaphase of meiosis II
E. none of the above

D. metaphase of meiosis II

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8.
The second meiotic division differs from the first meiotic division in that:
A. crossing over only occurs during meiosis I
B. there is pairing of the homologous chromosome during meiosis I
C. there is no DNA synthesis during meiosis II
D. all of the above
E. none of the above

D. all of the above

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9.
The zona pellucida:
A. is synthesized by the oocyte during oogenesis
B. contains species-specific sperm receptor molecules
C. is modified post-fertilization to block polyspermy
D. all of the above
E. none of the above

D. all of the above

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10.
Nondisjunction is the result of an abnormal meiotic division that:
A. is thought to occur during oogenesis
B. can result in autosomal trisomy
C. can result in an individual with 47 chromosomes
D. can be the result of homologous chromosomes failing to separate
E. all of the above are correct

E. all of the above are correct

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11.
During gametogenesis, meiosis occurs which reduces the chromosome number from _______ to _______.
A. diploid to haploid
B. haploid to tetraploid
C. dizygotic to monozygotic
D. bicornate to unicornate
E azygos to hemiazygos

A. diploid to haploid

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12.
The human male has how many different chromosomes?
A. 48
B. 46
C. 47
D. 24
E. 26

D. 24

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13.
As the follicle grows, the oogonium becomes located in a mound of follicle cells called the:
A. vesicular antrum
B. oocyte
C. cumulus oophorus
D. liquor folliculi
E. none of these

C. cumulus oophorus

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14.
How many different kinds of chromosomes are there in a human female?
A. 22
B. 23
C. 24
D. 25
E. 47

B. 23

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15. The secondary oocyte completes the second maturation division: A. before ovulation B. during ovulation C. at fertilization D. before birth E. before puberty

C. at fertilization

16. Spermatogonia, derived from primordial germ cells, divide by mitosis during: A. postnatal periods B. prenatal periods C. postnatal periods after puberty D. the reproductive period E. puberty

C. postnatal periods after puberty

17. The process of spermiogenesis involves, along with other events, the addition of a cap containing proteolytic enzymes to the head of the male sex cell. Immediately prior to spermiogenesis, the male sex cells are called_______________. A. spermatids B. primary oocytes C. secondary oocytes D. epididymis E. acrosomes F. spermatogonia G. oogonia H. cumulus oophorus I. spermatozoa J. polar bodies

A. spermatids

18. Immediately prior to ovulation, the first meiotic division, which had been arrested in prophase I, resumes. This transforms the developing sex cells into __________________, which becomes arrested again at the second metaphase of meiosis. A. spermatids B. primary oocytes C. secondary oocytes D. epididymis E. acrosomes F. spermatogonia G. oogonia H. cumulus oophorus I. spermatozoa J. polar bodies

C. secondary oocytes

19. Which meiosis phase (I or II) does replication of DNA/crossing-over and centromere division of chromosomes occur respectively? A. Meiosis II / meiosis I B. Meiosis I / meiosis II C. Meiosis I / meiosis I D. Meiosis II / meiosis II

B. Meiosis I / meiosis II

20. A 4-year-old healthy female presents to your office to establish primary care. What phase of meiosis should her oocytes be in? A. Meiosis I - prophase B. Meiosis II - prophase C. Meiosis I - metaphase D. Meiosis II - metaphase

A. Meiosis I - prophase

21. A 24 year-old healthy female presents for her pap smear. She has regular periods that last 5-7 days and occur every 30 days. She denies abnormal pain, bleeding, discharge, or history of positive pap smears. What phase of meiosis should her selected oocyte be in? A. Meiosis I - prophase B. Meiosis II - prophase C. Meiosis I - metaphase D. Meiosis II - metaphase

D. Meiosis II - metaphase

A 3 year-old male patient presents with epicanthal folds, flat nasal bridge, single palmar crease. The patient is 47 XY on karyotype. What could be the cause of this karyotype? A. Chromosomal mutation B. Chromosomal inversion C. Chromosomal nondisjunction D. Chromosomal deletion

C. Chromosomal nondisjunction

1. All of the following are directly involved with the implantation process except: A. decidual reaction B. progesterone C. epiblast D. invasion E. none of the above

E. none of the above

2. The seven-day blastocyst: A. has a single layer of trophoblast at the embryonic pole B. has an amniotic cavity C. is attached to the endometrial epithelium D. is surrounded by a degenerating zona pellucida E. is called the hypoblast

C. is attached to the endometrial epithelium

3. Which of the following are classified as gonadotropin hormones? A. FSH B. GnRH C. estradiol or estrogen D. progesterone E. all of the above

A. FSH

4. Haploid nuclei that fuse at fertilization are called: A. homunculi B. mitotic figures C. centrioles D. nucleoli E. pronuclei

E. pronuclei

5. The first week of human development is characterized by formation of the: A. inner cell mass B. hypoblast C. trophoblast D. blastocyst E. all of the above

E. all of the above

6. During the follicular phase of the menstrual cycle: A. FSH binds to the corpus luteum and stimulates estrogen production B. FSH binds to granulosa cells of the follicle and stimulates estrogen production C. FSH binds to the corpus luteum and stimulate progesterone production D. FSH binds to granulosa cells of the follicle and stimulates progesterone production E. FSH binds to granulosa cells of the follicle and stimulates LH production

B. FSH binds to granulosa cells of the follicle and stimulates estrogen production

7. Gonadotropin-releasing hormone or GnRH: A. acts on the hypothalamus, causing release of FSH & LH B. is released once a month from the corpus luteum C. acts on anterior pituitary gland, causing release of FSH & LH D. acts on the anterior pituitary causing release of estrogen and progesterone E. is one of those meaningless substances that scientists play with in lieu of working for a living

C. acts on anterior pituitary gland, causing release of FSH & LH

8. The LH surge: A. results in ovulation B. triggers resumption of meiosis within the oocyte C. is caused by a positive feedback effect of estrogen D. all of the above E. none of the above

D. all of the above

9. The luteal/progestational/secretory phase of the menstrual cycle is characterized by: A. high circulating levels of FSH and LH B. high circulating levels of progesterone C. an extreme variation in length from cycle to cycle D. a thin, non-vascularized endometrium E. none of the above

B. high circulating levels of progesterone

10. The second polar body: A. is released upon stimulation of the follicle by FSH B. is released as a result of the LH surge C. is released after fertilization D. is released after pronuclear formation E. is also known as the south pole

C. is released after fertilization

11. The corpus luteum: A. is only functional during the follicular phase of the menstrual cycle B. has receptors for progesterone and estrogen C. is rescued from decline by hCG secreted by the implanted embryo D. produces both FSH and LH E. none of the above

C. is rescued from decline by hCG secreted by the implanted embryo

12. During implantation, the blastocyst: A. implants in the endometrium B. usually attaches to endometrial epithelium at its embryonic pole C. usually implants in the posterior wall of the body of the uterus D. causes change in the endometrial tissues E. all of the above are correct

E. all of the above are correct

13. Capacitation of the sperm: A. is caused by the zona pellucida B. occurs in the male C. prevents polyspermy D. is essential for fertilization E. removes the head of the sperm

D. is essential for fertilization

14. The most significant factors in sperm transport to the vicinity of the oocyte is: A. sperm flagellum (tail) B. vaginal cilia C. an intact zona pellucida D. smooth muscle contractions E. gravity

A. sperm flagellum (tail)

15. The early stages of cleavage are characterized by: A. formation of a hollow ball of cells B. formation of the zona pellucida C. increase in the size of the cells in the zygote D. increase in the number of cells in the zygote E. none of the above

D. increase in the number of cells in the zygote

The most common site for implantation in ectopic pregnancy is: internal os of the uterus A. mesentery B. ovary C. uterine tube D. other

C. uterine tube

17. During the morula stage: A. tight junctions appear between peripheral cells, isolating the inner cells from uterine fluid B. the location of the cells dictates their fate C. the outer cells pump fluid, creating a fluid- filled blastocoel D. attachment to the uterine epithelium has not yet occurred E. all of the above are correct

E. all of the above are correct

18. Capacitation of spermatozoa is an activation process that involves changes in the surface coat and plasma membrane over the ________. A. tail B. body C. acrosome D. nucleus

C. acrosome

19. Implantation will not take place unless the zona _________ is lost. A. pellucida B. limitans C. orbicularis D. corona E. oophorus

A. pellucida

20. The results of fertilization include the determination of chromosomal sex and initiation of cleavage. A. true B. false

A. true

21. Before a spermatozoan can fertilize an ovum: A. the cell membrane is removed from the spermatozoan head B. the zona pellucida must be shed C. the acrosomal membrane must perforate D. the tailpiece is lost E. the decidua reaction must occur

C. the acrosomal membrane must perforate

22. At fertilization: A. the haploid number of chromosomes is restored B. the chromosomal sex is determined C. cleavage is inhibited D. the inner cell mass becomes recognizable E. the ovum becomes the blastocyst

B. the chromosomal sex is determined

23. Which of the following events are directly related to implantation? A. interaction between uterine endometrium and hypoblast B. release of proteolytic enzymes C. loss of the decidua D. acrosome reaction E. capacitation

A. interaction between uterine endometrium and hypoblast

24. In ectopic pregnancy: A. the placenta overbridges the internal os of the uterus B. implantation is inside the uterus C. severe bleeding is present during vaginal delivery D. the most common site is the uterine tube

D. the most common site is the uterine tube

25. Approximately how many million sperm are there in the average ejaculate of 3.5 cc? A. 5 B. 50 C. 100 D. 200 E. more than 200

26. The meeting and union of human sex cells is believed to occur in the: A. upper third of the uterine tube B. middle third of the uterine tube C. lower third of the uterine tube D. uterus E. cervix

A. upper third of the uterine tube (AMPULLA)

27. Sexuality is established at the time of: A. ovulation B. gametogenesis C. histogenesis D. morphogenesis E. none of the above

E. none of the above

28. Cleavage divisions are always: A. meiotic B. mitotic C. amniotic D. anucleotic E. by binary fission

B. mitotic

29. At which of the following stages of development is division of embryonic material likely to result in normal monozygotic twinning? A. 2-cell stage B. morula C. blastocyst D. implanting embryo E. all of the above

C. blastocyst

The fifth day of human development is characterized by embryonic cells of the: A. inner cell mass B. embryonic hypoblast C. epiblast D. primitive streak E. amnion

A. inner cell mass

The _______ is/are part(s) of the 4-day blastocyst: A. syncytiotrophoblast B. blastocyst cavity C. notochord D. somitomeres

A. syncytiotrophoblast B. blastocyst cavity

Why do all mitochondria DNA of the embryo come from the mother? A. Sperm do not contain mitochondria B. Head and tail of sperm degrade upon fertilization C. Cell division process leaves out mitochondria DNA from sperm D. Mitochondrial DNA of sperm is degraded upon entering egg

D. Mitochondrial DNA of sperm is degraded upon entering egg

Where is the normal location of initial implantation of the embryo? A. Posterior superior wall of uterus B. Anterior posterior wall of uterus C. Lateral superior wall of uterus D. Medial posterior wall of uterus E. Ampulla of uterine tube

A. Posterior superior wall of uterus

Practice Questions Flashcards

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