First Three Weeks Of Development – Practice Questions
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- 1.All of the following structures are necessary for blastocyst implantation EXCEPT?
- A.
All of the following structures are necessary for blastocyst implantation EXCEPT?
- B.
Zona pellucida
- C.
Syncytiotrophoblast
- D.
Cytotrophoblast
- E.
Functional layer of endometrium
- 2.A 20-year old woman presents at the ER with severe abdominal pain on the right side with signs of abdominal bleeding. She indicated that she has been sexually active without contraception and missed her last menstrual period. Based on this information, which of the following disorders must be included as an option in the diagnosis?
- A.
Ovarian cancer
- B.
Appendicitis
- C.
Normal pregnancy
- D.
Ectopic tubal pregnancy
- E.
Toxemia of pregnancy
- 3.Mesoderm is formed from
- A.
A) Hypoblast cells
- B.
B) Extraembryonic ectoderm
- C.
C) Notochordal cells
- D.
D) Epiblast cells
- E.
E) Amnioblasts
- 4.. Which of the following statements regarding the uteroplacental circulation is CORRECT?
- A.
A) Lacunae form within the cytotrophoblast
- B.
B) Hydrolytic enzymes produced by the trophoblast degrade the endothelium of embryonic capillaries
- C.
C) It is established during the second week of development
- D.
D) It is a transient nutrient supply for the blastocyst during implantation
- E.
E) It only forms in ectopic implantations
- 5.Between which two layers is the extraembryonic mesoderm located?
- A.
A) Exocoelomic membrane and cytotrophoblast
- B.
B) Epiblast and hypoblast
- C.
C) Syncytiotrophoblast and endometrium
- D.
D) Exocoelomic membrane and syncytiotrophoblast
- E.
E) Syncytiotrophoblast and cytotrophoblast
- 6.Which of the following statements regarding the epiblast is CORRECT?
- A.
A) It is composed of small cuboidal cells
- B.
B) It forms the roof of the blastocyst cavity
- C.
C) It forms the primitive streak
- D.
D) Notochordal cells intercalate into it
- 7.A young woman was exposed to rubella virus during pregnancy which resulted in her having a baby with ventriculoseptal cardiac defect. In which period was the mother most likely to have contracted the acute viral infection?
- A.
A) Weeks 1-5 before fertilization
- B.
B) Weeks 1-5 after fertilization
- C.
C) Months 4-5 after fertilization
- D.
D) Months 5-6 after fertilization
- E.
E) Weeks 9 to 12 after fertilization
- 8.The process of gastrulation is first indicated by the formation of the
- A.
A) Prechordal plate
- B.
B) Cloacal membrane
- C.
C) Primitive streak
- D.
D) Neural tube
- E.
E) somites
- 9.
- A.
A) Hydatidiform mole
- B.
A) Premature rupture of the amniotic membrane
- C.
B) Placenta previa
- D.
C) Toxemia of pregnancy
- E.
D) Vasa previa
- 10.True or false? Intraembryonic mesoderm is located between the endoderm and ectoderm at the buccopharyngeal membrane but not the cloacal membrane
- A.
True
- B.
False
- 11.A newborn presents with craniofacial abnormalities and a cardiac defect involving the outflow tract of the heart. Why are you not surprised?
- A.
A) Paraxial mesoderm contributes to formation of both areas
- B.
B) HOX genes contribute to both areas and could be involved
- C.
C) Body folding is important for both areas and may produce combined defects
- D.
D) The mother took fertility drugs
- E.
E) Neural crest cells contribute greatly to development of both regions
- 12.Which of the following is NOT derived from ectoderm?
- A.
A) Epidermis
- B.
B) Enamel of teeth
- C.
C) Dermis of skin
- D.
D) Forebrain
- E.
E) Mammary gland
- 13.. If an embryo failed to form the mesoderm germ layer which of the following would not develop?
- A.
A) hindbrain
- B.
B) Schwann cells
- C.
C) aorta
- D.
D) intestinal epithelia
- E.
E) nails
- 14.Where do ectopic pregnancies most often occur?
- A.
A) Ovary
- B.
B) Mesentery of the intestine
- C.
C) Abdomen
- D.
D) ampullae region of uterine tube
- E.
E) isthmus region of uterine tube
- 15.Which of the following will form the lens of the eye?
- A.
A) lateral plate mesoderm
- B.
B) ectoderm
- C.
C) neural crest cells
- D.
D) endoderm
- E.
E) intermediate mesoderm
- 16.Splitting of the lateral plate mesoderm forms the
- A.
A) somites
- B.
B) paraxial and intermediate mesoderm
- C.
C) yolk sac cavity
- D.
D) intraembryonic cavity
- E.
E) amniotic cavity
- 17.Where are melanocytes derived from?
- A.
A) mesoderm
- B.
B) mesenchyme
- C.
C) ectoderm
- D.
D) neural crest cells
- E.
E) dermis
- 18.What portion of the blastocyst will give rise to the embryo?
- A.
A) cytotrophoblast
- B.
B) outer cell mass
- C.
C) endoderm
- D.
D) inner cell mass
- E.
E) ectoderm
- 19.Where are the excretory units of the urinary system derived from?
- A.
A) endoderm
- B.
B) lateral plate mesoderm
- C.
C) ectoderm
- D.
D) splanchnic mesoderm
- E.
E) intermediate mesoderm
- 20.A sacrococcygeal teratoma is a tumor that arises from remnants of the
- A.
A) Neural plate
- B.
B) Cloacal membrane
- C.
C) Posterior neuropore
- D.
D) Primitive streak
- E.
E) Notochord
- 21.The amniotic cavity appears on the eighth day as a slit-like space between the trophoblast and the
- A.
A) extraembryonic mesoderm
- B.
B) embryoblast
- C.
C) exocoelomic membrane
- D.
D) connecting stalk
- E.
E) chorion
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