Question 1
Question
Haploid nuclei that fuse at fertilization are called:
Answer
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homunculi
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mitotic figures
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centrioles
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nucleoli
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pronuclei
Question 2
Question
The first week of human development is characterized by formation of the:
Answer
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inner cell mass
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hypoblast
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trophoblast
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blastocyst
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all of the above
Question 3
Question
During implantation, the blastocyst:
Answer
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implants in the endometrium
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usually attaches to endometrial epithelium at its embryonic pole
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usually implants in the posterior wall of the body of the uterus
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causes change in the endometrial tissues
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all of the above are correct
Question 4
Question
Capacitation of the sperm:
Answer
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is caused by the zona pellucida
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occurs in the male
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prevents polyspermy
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is essential for fertilization
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removes the head of the sperm
Question 5
Question
The early stages of cleavage are characterized by:
Answer
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formation of a hollow ball of cells
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formation of the zona pellucida
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increase in the size of the cells in the zygote
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increase in the number of cells in the zygote
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none of the above
Question 6
Question
The amniotic cavity develops:
Answer
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on the tenth day
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within the outer cell mass
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within the inner cell mass near the cytotrophoblast
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in extraembryonic mesoderm
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none of the above
Question 7
Question
During the second week of development, the trophoblast differentiates into:
Answer
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syncytiotrophoblast
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ectoderm
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intraembryonic mesoderm
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yolk sac (secondary)
Question 8
Question
The first two intraembryonic germ layers to differentiate are the:
Answer
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ectoderm and hypoblast
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epiblast and hypoblast
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ectoderm and endoderm
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ectoderm and mesoderm
Question 9
Question
The blastocoele becomes the:
Answer
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amniotic cavity
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extraembryonic coelom
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primary yolk sac
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chorionic cavity
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secondary cavity
Question 10
Question
The bilaminar germ disc:
Answer
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consists of epiblast and mesoblast
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is derived from the outer cells of the morula
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forms the embryo proper
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synthesizes human chorionic gonadotropin, HCG
Question 11
Question
The primitive streak first appears at the beginning of the _____ week.
Answer
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first
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second
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third
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fourth
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fifth
Question 12
Question
Which of the following structures is believed to be a primary organizer or inducer during organogenesis?
Answer
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somites
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notochord
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metanephric blastema
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lens placode
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none of the above
Question 13
Question
Cells from the primitive streak DO NOT become:
Answer
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endoderm
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intermediate mesoderm
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paraxial mesoderm
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lateral plate mesoderm
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amnioblasts
Question 14
Question
The primitive streak:
Answer
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is derived from the outer cells of the morula
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is formed during the second week in development
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persists as the cloacal membrane
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is the site of involution of epiblast cells to form mesoderm
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was done in a bathing suit, for those who remember streaking
Question 15
Question
In the third week of human embryonic development:
Answer
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the amnion appears
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a bilaminar embryonic disc is formed
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the body stalk moves ventrally and joins with the yolk sac stalk to form the umbilical cord
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the neural plate is induced by the notochordal process and associated mesoderm
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the uteroplacental circulation is established
Question 16
Question
During development, the notochordal process:
Answer
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arises from involuting endodermal cells
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extends from the prochordal plate to the primitive node
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is involved in the induction of the primitive gut
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becomes the appendicular skeleton
Question 17
Question
The following organs are derived from mesoderm EXCEPT:
Question 18
Answer
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differentiate into myotomes which give rise to skeletal muscle in trunk and limbs
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differentiate into sclerotomes which give rise to vertebrae
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arise from segmentation of the paraxial mesoderm
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differentiate into myotomes which give rise to skeletal muscle of the limbs
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all of the above are correct
Question 19
Question
Almost all of the internal organs are well laid down at _____ months.
Question 20
Question
The notochord is replaced by the:
Answer
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ependyma
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nucleus pulposus
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spinal canal
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dorsal roots
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spinal cord
Question 21
Question
After folding of the head region, the structure lying just caudal to the pericardial cavity is the:
Answer
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developing heart
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connecting stalk
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primitive streak
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liver
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septum transversum
Question 22
Question
The fact that general and special sensory information from the posterior part of the tongue is carried by glossopharyngeal nerve indicates that this part of tongue is from branchial arch _____.
Question 23
Question
As a resident in pediatrics, you are called to see a newborn who has a unilateral cleft lip and a unilateral cleft of the primary palate. This condition is most likely the result of:
Answer
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failure of fusion of the mandibular prominences
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failure of fusion of the medial nasal processes
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failure of fusion of the maxillary prominence with the medial nasal prominence
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failure of fusion of the lateral palatine processes with the nasal septum
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failure of fusion of the paired lateral palatine processes.
Question 24
Question
Which of the following structures is NOT part of the first branchial arch?
Question 25
Question
Which structures are derived from the intermaxillary segment of the embryonic face?
Answer
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philtrum
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anterior portion of the palate
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anterior portion of the upper jaws
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upper incisor teeth
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all of the above are correct
Question 26
Question
The foramen cecum of the adult tongue:
Answer
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marks the point of embryonic evagination of the thymus gland
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divides the tongue into two parts, an anterior one-third and a posterior two-thirds
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marks the point of embryonic evagination of the thyroid gland
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develops into taste buds
-
has no embryologic significance
Question 27
Question
Each pharyngeal arch includes:
Question 28
Question
Which of the following are associated with the 2nd pharyngeal arch?
Question 29
Question
The tracheoesophageal septum separates the:
Answer
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laryngotracheal tube and nasopharynx
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esophagus and nasopharynx
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laryngotracheal tube and esophagus
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laryngotracheal tube and oropharynx
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esophagus and oropharynx
Question 30
Question
A 28-year-old woman who does not know that she is pregnant undergoes a chemotherapy treatment at the end of her 1st week of pregnancy. Chemotherapy is associated with slowing the rate of mitosis in exposed cells, which is good in cancer treatment. However, this treatment may also have a negative influence on the implantation and growth of an embryo. In which of the following layers would a lowered rate of cell division be most likely to hinder implantation of the blastocyst?
Answer
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Amnioblast
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Epiblast
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Hypoblast
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Cytotrophoblast
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Syncytiotrophoblast