VI. Embryology questions
Embryology practice questions
There are a total of 32 embryology practice questions, which are important content-oriented in the summary part of this chapter. Click the ‘Answer’ button to see the corresponding answers and explanations, and click the ‘Go back’ button to slove the next questions.
1. Which of the following is correct passage of sperm?
A. Vas deferens → epididymis → ejaculation duct → penis
B. Vas deferens → ejaculation duct → epididymis → urethra
C. Testis → epididymis → vas deferens → urethra
D. Testis → vas deferens → ejaculation duct → epididymis
E. Epididymis → ejaculation duct → vas deferens → penis
2. Which of the following is a diploid cell during oogenesis?
A. Secondary polar body
B. Primary oocyte
C. First polar body
D. Secondary oocyte
E. Ovum
3. Which of the following CANNOT happen to a pregnant female?
A. The temperature of her body is changed.
B. The secretion of LH and FSH are increased.
C. Degeneration of the corpus luteum does not occur.
D. A large amount of progesterone is found.
E. The thickness of the endometrium is maintained.
4. Which of the following describe(s) the human reproductive system correctly?
I. Single zygote becoming a different and specialized system of tissues is called cell differentiation. II. Identical twins have exactly the same body shapes, even fingerprints, between two fetuses, because a single zygote, one egg and sperm, divides into two identical embryos. III. Fraternal twins means that two eggs fertilized by two separate sperm become twins. IV. The male urethra shares excretory and reproductive systems. |
A. I and II
B. I and III
C. II, III, and IV
D. I, II, and III
E. I, III, and IV
5. The respiratory system and digestive system are derived from _____________ .
A. Ectoderm
B. Mesoderm
C. Endoderm
D. Somite
E. Notochord
6. Which of the following the parts of the egg for fertilization is an INCORRECTLY matched pair for the name and its function or features?
A. Jelly coat: material for the sperm to attach on the surface of eggs
B. Vitelline layer: position between jelly coat and plasma membrane
C. Cortical granules: blocking polyspermy
D. Zona pellucida: intracellular matrix of egg
E. Sperm binding receptor: placed at vitelline layer
7. Which of the following is FALSE?
A. Acid secreted from the vagina has a function similar to the HCl of stomach.
B. During oogenesis only one big ovum is produced, because it must get nutrients for the process of fertilization and the zygote.
C. Ovulation is controlled by LH.
D. The menstrual cycle is repeated with the follicular phase and luteal phase.
E. All are correct.
8. Which of the following is derived from a different germ layer than the others?
A. Epidermis of skin
B. Muscular system
C. Circulatory system
D. Skeletal system
E. Lymphatic system
9. Which of the following is an INCORRECT statement?
A. Umbilical veins are for passage of oxygen and nutrients from maternal arteries.
B. Umbilical arteries send waste materials to maternal veins.
C. The placenta between maternal arteries and umbilical veins is connected directly.
D. Implantation happens in the uterus.
E. Even mammalian embryos have amnion, chorion, and yolk sac.
10. After birth the infant grows with different rates of different body parts. This is called _____________ .
A. Allomatic growth
B. Cell differentiation
C. Induction
D. Morphogenesis
E. Cytoplasmic determinants
11. Which of the following sperm structures contains hydrolytic enzymes to penetrate eggs during fertilization?
A. Nucleus
B. Flagellum
C. Mitochondria
D. Acrosome
E. Midpiece
12. Which of the following is the place for fertilization of sperm and egg in the female reproductive system?
A. Vagina
B. Cervix
C. Uterus
D. Fallopian tube
E. Ovary
13. Which of the following is an INCORRECTLY matched pair for the name and its function or features?
A. Follicle: egg cell consisting of oocyte and follicle cells layer
B. Corpus luteum: secreting LH and FSH
C. Ovulation: releasing of an egg to oviduct
D. Ovary: place of oogenesis
E. Uterus: place of implantation of fertilized egg
14. What is a cortical reaction in sea urchin development?
A. Contacting sperm head to the egg surface
B. Fast block to polyspermy
C. Insertion of sperm nucleus
D. Transformation the vitelline layer into a fertilization envelope
E. Fusing jelly coat by hydrolytic enzymes of acrosome
15. At the time of insertion of the sperm nucleus, the fast block to polyspermy occurs. What is this called?
A. Acrosomal reaction
B. Depolarization
C. Cortical reaction
D. Contacting
E. Approaching
16. Which of the following is the correct sequential order of embryonic developmental stages?
A. Morulation → blastulation → gastrulation → induction
B. Induction → morulation → gastrulation → neurulation
C. Cleavage → neurulation → induction → gastrulation
D. Cleavage → Induction → gastrulation → morulation
E. Blastulation → gastrulation → induction → cleavage
17. Which of the following is correct passage of placental circulation?
A. Maternal veins → embryo → umbilical veins → maternal arteries
B. Maternal arteries → umbilical arteries → embryo → umbilical veins
C. Umbilical veins → embryo → umbilical arteries → maternal arteries
D. Maternal arteries → umbilical veins → embryo → umbilical arteries
E. Maternal veins → umbilical arteries → embryo → umbilical veins
18. Which of the following correctly describe(s) postnatal development?
Ⅰ. Infants produce adult-like hemoglobin. Ⅱ. Foramen ovale is degenerated. Ⅲ. Pressure of the left atrium is increased. |
A. I only
B. I and II
C. I, II, and III
D. II, III, and IV
E. All of the above
19. Which of the following statements about female reproduction are true?
Ⅰ. Oogenesis happens in the ovary. Ⅱ. The ovum is a result of equally distributed cytoplasm. Ⅲ. Reducing chromosome from diploid to haploid means that the primary oocyte is divided into a secondary oocyte and the first polar body. Ⅳ. The ruptured follicle becomes the corpus luteum. |
A. I only
B. I and III
C. I, II, and III
D. I, III, and IV
E. All of the above
20. Which of the following is an INCORRECT statement about menstrual periods?
A. Endometrium becomes thick after ovulation.
B. During follicle growth the secretion of LH and FSH are increased.
C. After ovulation the secretion of estrogen and progesterone are decreased.
D. Increasing the secretion of progesterone hinders ovulation.
E. Meiosis happens in the ovary.
21. Choose an INCORRECT statement.
A. During fertilization the nucleus of the sperm can enter into the egg.
B. Depolarization and cortical reaction hinder the insertion of polyspermy.
C. At the time of fertilization, many reactions of DNA synthesis and meiosis occur.
D. Fertilization happens in the oviduct but implantation and growing of the fertilized egg occurs in the uterus.
E. All are correct.
22. Which of the following is the stage of embryonic development forming a hollow ball of cells?
A. Morula
B. Blastula
C. Gastrula
D. Blastopore
E. Organogenesis
23. Which of the following extraembryonic membranes encloses a chamber for providing nutrients to a bird embryo?
A. Yolk sac
B. Allantois
C. Chorion
D. Amnion
E. Shell
24. Which of the following is an INCORRECTLY matched pair for the name and its function?
A. Seminiferous tubules: production of sperm
B. Epididymis: maturation of sperm
C. Leydig cells: synthesis of androgen and testosterone
D. Vas deferens: storage of sperm
E. Prostate gland: neutralizing the acidity of the vaginal tract
25. Which hormones may be used for birth control?
A. LH, FSH
B. Estrogen, progesterone
C. Oxytocin, Prolactin
D. GH, TSH
E. ADH, Aldosterone
26. When does the peak of LH and FSH occur?
A. At the beginning of the follicular phase
B. After the luteal phase
C. Before ovulation
D. After ovulation
E. Before maximum thickening of the endometrium
27. Which of the following structures is derived from ectoderm?
A. Heart
B. Lung
C. Tooth
D. Muscle
E. Pancreas
28. Which of the following is NOT related to gastrulation?
A. Formation of three germ layers
B. Neural tube
C. U-shaped structure
D. Archenteron
E. Dorsal lip
29. All of the following are true of amnion EXCEPT _______________.
A. Present in human
B. Present in amphibians
C. Membranous sac
D. Protects embryo from mechanical shock
E. Covers embryo
30. The places for exchanging food and wastes between fetus and maternal tissues are called _____________.
A. Chorion
B. Umbilical veins
C. Umbilical arteries
D. Placenta
E. Amnion
31. Which of the following is a FALSE statement?
A. Spermatogenesis is controlled by FSH and testosterone.
B. Spermatogenesis produces sperm, which are equally distributed cytoplasm.
C. Leydig cells are stimulated by LH to synthesize androgen and testosterone.
D. The flagellum is used for movement of sperm.
E. All are correct.
32. Which of the following is the function of allantois?
A. Disposal sac for embryo wastes
B. Membranous sac for embryo nutrients
C. Develops into the placenta in humans
D. Protects embryo from mechanical shock and dehydration
E. A and C
Answers
1. C
Correct passage of sperm:
Testis → epididymis → vas deferens → ejaculation duct → urethra → penis
2. B
The oogonium and primary oocyte are diploid cells. The secondary oocyte, first polar body, ovum, and second polar body are haploid cells.
3. B
When sperm and egg meet, it comes to be a zygote and is then implanted in the lining of the uterus. During this time the corpus luteum keeps releasing estrogens and progesterone for promoting uterine lining growth. Increased secretion of LH and FSH does not occur.
4. E
Two identical embryos from a single zygote, one egg and sperm, is called identical twins. However, they are not exactly same because they get different amounts of nutrients from the mother and they even develop in slightly different environments.
5. C
The respiratory system, digestive system, and urinary bladder are derived from endoderm. The somite and notochord are derived from mesoderm.
6. D
Zona pellucida is the extracellular matrix of egg for sperm receptor of internal fertilization of mammals.
8. A
The epidermis of skin is derived from ectoderm and the rest of the above are derived from mesoderm.
9. C
The maternal arteries and umbilical veins are afloat in sinus containing maternal blood, and they are connected indirectly.
10. A
Cell differentiation means that a single zygote becomes a specialized system of tissues in multicellular organisms. Induction means that one part of embryonic cells influence the growth of another. Morphogenesis means that the differentiated cells are placed at proper locations. Substances that regulate differention of embryonic cells are called cytoplasmic determinants.
11. D
The head of the sperm has an acrosome to penetrate the envelop of the egg and insert the nucleus into the egg.
12. D
The Fallopian tube, also called the oviduct, is place of fertilization and passage of the egg.
14. D
Cortical reaction is when the release of a cortical granule transforms the vitelline layer into a fertilization envelope and causes a slow block to polyspermy. A is the contact stage and B is depolarization. E is the acrosomal reaction.
15. B
The plasma membrane is fused by the inserted sperm nucleus, which causes the membrane to be potentially charged and then the fast block to polyspermy occurs.
16. A
Correct order of embryonic developmental stages:
Cleavage(morulation → blastulation) → gastrulation → organogenesis(neurulation, induction)
17. D
Correct passage of placental circulation:
Maternal arteries → umbilical veins → embryo → umbilical arteries → maternal veins
18. E
After birth the infant begins producing hemoglobin, degenerating the foramen ovale, increasing the pressure of the left atrium, and decreasing the pressure of the right atrium and pulmonary arteries
19. D
All are true exceptⅡ. Unlike oogenesis in the female, the equally distributed cytoplasm happens in spermatogenesis in the male.
20. C
After ovulation the corpus luteum secretes estrogen and progesterone for preparing the uterine lining for growth and implantation of the zygote.
21. C
After fertilization many reactions of DNA synthesis and mitosis happen. Meiosis only occurs in the ovary of the female and seminiferous tubules of the male.
22. B
A blastula of the cleavage stage forms a hollow ball of cells and blastocoels (fluid-filled cavities). A morula of the cleavage stage forms a solid ball of cells. A gastrula forms three germ layers (ectoderm, mesoderm, and endoderm). The blastopore is the end of archenterons, becoming a protostomal mouth or deuterostomal anus. The stage of organogenesis forms the different rudiments of organs from the three germ layers.
23. A
York sac provides nutrients to embryo. Allantois is a disposal sac for liquid waste from embryo and functions in respiration. Chorion is membrane for exchanging gases between embryo and outside membrane. Amnion is membranous sac for protecting an embryo from mechanical shock and dehydration.
24. D
All are correct except D. The Vas deferens is a duct for expulsion of sperm. The place for storage and maturation of sperm is the epididymis.
25. B
Estrogen and progesterone inhibit secretion of LH and FSH hormones, which stimulate ovaries in the process of ovulation.
26. C
The peak of LH and FSH happens just before ovulation and the peak of progesterone and estrogen happens before maximum thickening of the endometrium.
27. C
Epidermis of skin, sensory receptor, nervous system, and teeth are derived from ectoderm. Circulatory system (heart, blood vessels) and muscular system are derived from mesoderm. Respiratory system (lungs) and digestive system (pancreas) are derived from endoderm.
28. B
During gastrulation the process of invagination becomes a dorsal lip and forms a U-shaped structure of archenterons and three germ layers (ectoderm, mesoderm, endoderm). The neural tube forms late in neurulation.
30. D
At the placenta, a fetus obtains nutrients from maternal arteries and excretes wastes to maternal veins.
31. E
FSH secreted by the anterior pituitary and testosterone secreted by Leydig cells regulate spermatogenesis. The flagellum is worked by ATP, which is produced by many mitochondria in the sperm.
32. E
Allantois functions as a disposal sac for wastes and respiration in shelled eggs. It becomes the placenta in mammals.