AN223 MCQ exam …..

During spermatogenesis which cells are the product of the second meiotic division?
a. Spermatogonia
b. Primary spermatocyctes
c. Secondary spermatocytes
d. Spermatozoon
e. Spermatids

Spermatozoon

Down's Syndrome is the result of trisomy of chromosome
a) 5
b) 18
c) 21
d) 12
e) 8

c) 21

What is a 16 cell embryo is called? a) Hypoblast b) Blastocyst c) Morula d) Fetus e) Syncytiotophoblast

Morula

How long does the embryonic period last in humans? a) 2 Weeks b) 4 Weeks c) 8 Weeks d) 16 Weeks e) 32 Weeks

8 Weeks

Which of the following cells can divide by mitosis? a) Spermatid b) Secondary Oocyte c) Spermatogonia d) Primary oocyte e) Spermatozoon

Spermatogonia

From the following list of substances is most likely to cause limb defects in human embryos. a) Alcohol b) Tobacco c) Asprin d) Thalidomide e) Rubella virus

Thalidomide

Which of the following is the name of the protective coat of the secondary Oocyte? a. Corona radiata b. Zona pellucida c. Cytoplasm d. Acrosomal cap e. Polar body

Zona pellucida

During the second week lacunar networks develop within the
a. cytotrophoblast
b. inner cell mass
c. syncytiotrophoblast
d. endometrium
e. extraembryonic mesoderm

syncytiotrophoblast

Which of the following is not a feature of the second week of human life?
a) Completion of implantation
b) Formation of a bilaminar embryo
c) Formation of the sclerotome
d) Formation of the amniotic cavity
e) The beginning of utero-placental circulation

c

The trophoblast divides into which of the following structures?
a) Epiblast and hypoblast
b) Amniotic sac and yolk sac
c) Endoderm and mesoderm
d) Cytotrophoblast and syncytiotrophoblast
e) Sclerotome and dermomyotome

d) Cytotrophoblast and syncytiotrophoblast

What germ layer or derivation does cerebral tissue arise from?
a. Ectoderm
b. Endoderm
c. First pharyngeal arch
d. Mesoderm
e. Neural crest cells

Ectoderm

Which of the following structures is derived from ectoderm:
a. Muscle
b. Cartilage
c. Blood vessels
d. Bone
e. Epidermis

Epidermis

The primitive streak
a. Is cranial to the primitive node
b. Is caudal to the notochord
c. becomes axial skeleton
d. Is a thickening of endoderm
e. Induces formation of the neural tube

b. Is caudal to the notochord

The tissue from which the primitive gut tube originates is:
a. Endoderm
b. Intermediate mesoderm
c. Lateral plate of the mesoderm (lateral mesoderm)
d. Paraxial mesoderm
e. The ectoderm

a. endoderm

In relation to endoderm which of the following statements is true?
a) becomes the neural tube
b) becomes the precursor of the gut tube
c) is frist visible after 8 weeks
d) is derived from the trophoblast
e) gives rise to the dermis of skin

b) becomes the precursor of the gut tube

Which part of the primitive heart tube gives rise to the pulmonary trunk and the aorta?
a) Bulbus cordis
b) Primitive atrium
c) Primitive ventricle
d) Sinus venosus
e) Truncus arteriosus

e) Truncus arteriosus

Which heart chamber does the right horn of the sinus venosus contribute to during development of the fetal heart?
a) Common ventricle
b) Left atrium
c) Left ventricle
d) Right atrium
e) Right ventricle

d) Right atrium

Which vessel transports blood rich in oxygen and nutrients from the placenta to the fetus?
a) Ductus arteriosus
b) Umbilical artery
c) Umbilical vein
d) Superior vena cava
e) Vitelline vein

c) Umbilical vein

The ductus arteriosus connects the:
a) Ascending aorta to the descending aorta
b) Pulmonary arteries with the pulmonary veins
c) Pulmonary arteries with the arch of the aorta
d) Pulmonary arteries with the ascending aorta
e) Pulmonary veins with the arch of the aorta

d) Pulmonary arteries with the ascending aorta

Which of the following secondary brain vesicles give rise to the lateral ventricles?
a. Diencephalon
b. Mesencephalon
c. Metencephalon
d. Myelencephalon
e. Telencephalon

e. Telencephalon

The round ligament of the liver (Ligamentum teres) is a remnant of which embryological structure?

Left umbilical vein

The ductus arteriosus is a remnant of which structure?

e. Left 6th aortic arch

The falciform ligament is derived from what embryological structure?

ventral mesentery

The intestinal loop undergoes what degree of rotation during development?

e. 270 anticlockwise

Which portion of the foregut becomes secondarily retroperitoneal?
a. The pylorus of the stomach
b. The lesser curvature of the stomach
c. The 2nd part of the duodenum
d. The ileum
e. The (vermiform) appendix

c. The 2nd part of the duodenum

From what are the cartilages of the conducting portion of the respiratory system derived:
a. Foregut endoderm
b. Oral ectoderm
c. Paraxial mesoderm
d. Splanchnic mesoderm
e. Extraembryonic mesoderm

d. Splanchnic mesoderm

Which of the phases of lung development is characterized by development of the definitive respiratory tissue:
a. Pseudoglandular phase
b. Canalicular phase
c. Terminal saccular phase
d. Alveolar phase
e. Maturation phase

b. Canalicular phase

Pulmonary surfactant is produced by:
a) Type I pneumocytes
b) Blood cells
c) alveolar macrophages
d) endothelial cells
e) type II pneumocytes

e) type II pneumocytes

The connective tissue, cartilage and smooth muscle of the trachea are derived from the
a) Somatic mesoderm of the lateral plates
b) Splanchnic mesenchyme around the laryngotracheal tube
c) Endodermal lining of the laryngotracheal tube
d) Neural crest
e) Mesenchyme of the 4th to 6th pairs of pharyngeal arches

b) Splanchnic mesenchyme around the laryngotracheal tube

The first indication of the lower respiratory tract in the human embryo is the laryngotracheal groove. It begins to develop in the primordial pharyngeal floor at _______ days

25-27

Which of the following structures is a derivative of the mesonephric duct?
a. The body of the uterus
b. The fallopian tubes
c. The nephrons
d. The penis
e. The vas deferens

e. The vas deferens

The nephric structures of the urinary system develop from :
a. Paraxial mesoderm
b. Ectoderm
c. Intermediate mesoderm
d. Lateral plate mesoderm
e. Endoderm

c. Intermediate mesoderm

The primitive kidneys (pronephroi) begin to develop during:
a. Week 3
b. Week 4
c. Week 5
d. Week 6
e. Week 7

b. Week 4 or week 3 not entirely sure

The human pronephros, a transitory non-functional kidney appears early in the 4th week as a few cell clusters in the _________ region of the embryo
a) occipital
b) cervical
c) thoracic
d) abdominal
e) pelvic

b) cervical

The metanephic diverticulum (ureteric bud)is derived from the
a) urogenital sinus
b) somatic mesoderm
c) mesonephric duct
d) metanephric mesoderm
e) paramesonephric duct

c) mesonephric duct

The paramesonephric ducts in female embryos give rise to the:
a) labia majora
b) uterine tubes
c) round ligament of the uterus
d) inferior part of the vagina
e) ovarian ligament

b) uterine tubes

Primordial germ cells are first recognizable in the 4th week in the
a) dorsal mesentery
b) primary sex cords
c) wall of the yolk sac
d) gonadal ridges
e) allantois

c) wall of the yolk sac

Which of the following swellings give rise to the labia minora:
a) genital
b) labioscrotal
c) urogenital
d) urorectal
e) labial

c) urogenital

The lower portion of the vagina is derived from
a) the pronephros
b) the mesonephric duct
c) the paramesonephric duct
d) the urogenital sinus
e) ureteric bud

d) the urogenital sinus

Penile hypospadias are common abnormalities of the male urethra they result from a failure of fusion of which embryonic structure:
a) Labioscrotal folds
b) Mesonephric ducts
c) Paramesonephric ducts
d) Gubernaculum testes
e) Urogenital folds

Urogenital

Which of the following types of germ cells does not undergo cell division?
spermatogonia
primary oocytes
spermatids
secondary oocytes
oogonia

spermatids

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

fetal life

How many sperms, approximately, are deposited in the vagina during intercourse?

300 million

The part of the sperm containing proteolytic enzymes to digest the zona pellucida is the:

acrosome

The ovulated mammalian oocyte is arrested at:
prophase of meiosis I
metaphase of meiosis I
prophase of meiosis II
metaphase of meiosis II
none of the above

metaphase of meiosis II

The first week of human development is characterized by formation of the:
inner cell mass
hypoblast
trophoblast
blastocyst
all of the above

all of the above

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

true

Before a spermatozoan can fertilize an ovum:
the cell membrane is removed from the spermatozoan head
the zona pellucida must be shed
the acrosomal membrane must perforate
the tailpiece is lost
the decidua reaction must occur

the acrosomal membrane must perforate

The fifth day of human development is characterized by embryonic cells of the:
inner cell mass
embryonic hypoblast
epiblast
primitive streak
amnion

inner cell mass

At the 32-cell stage of division, the embryo is known as a morula that contains inner cell mass and outer cell mass. What do the inner and outer cell masses eventually become?
Placenta / embryo and fetus
Embryo and fetus / placenta
Chorionic membrane / amniotic membrane
Amniotic membrane / chorionic membrane

Embryo and fetus / placenta

Where does the aminotic cavity develop?

within the inner cell mass
near the cytotrophoblast

The first two intraembryonic germ layers to differentiate are the:

epiblast & hypoblast

The blastocoele becomes the:

primary yolk sac

Extraembryonic somatic mesoderm is in close association with:

cytotrophoblast & amnion

The definitive yolk sac of the embryo appears by what day?

13th

Which layer is acellular, does not expand mitotically, and produces human chorionic gonadotropin (hCG) which stimulates progesterone production by the corpus luteum?

syncytiotrophoblast

The primitive streak first appears at the beginning of the ___ week.

3rd

what structure is a primary organizer or inducer during organogenesis?

notochord

The lining of the _____________ forms the lining of the embryonic gut.

secondary yolk sac

In the third week of human embryonic development:
the amnion appears
a bilaminar embryonic disc is formed
the body stalk moves ventrally and joins with the yolk sac stalk to form the umbilical cord
the neural plate is induced by the notochordal process and associated mesoderm
the uteroplacental circulation is established

the neural plate is induced by the notochordal process and associated mesoderm

Intraembryonic mesoderm differentiates into the:
yolk sac
neural tube
intermediate mesoderm
primordial germ cells

intermediate mesoderm

what gives rise to the wall of the gut tube?

splanchnic layer of the lateral plate mesoderm.

At end of third week, somites begin to develop along the notochord and neural tube. What do they end up forming?
axial skeleton
brain
spinal cord
sympathetic chain ganglia
limbs

axial skeleton

Of the following, the item most closely associated with the pons is:
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon

metencephalon

Of the following, the one most closely associated with the cerebrum is:
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon

telencephalon

Of the following, the one most closely associated with the 3rd ventricle is:

diencephalon

the pontine flexure is in a direction opposite the

mesencephalic and cervical flexure

The brain flexure which develops between the metencephalon and the myelencephalon is called the:

pontine

the inferior vena cava is derived from:
left vitelline vein
right vitelline vein
right umbilical vein
left umbilical vein
sinus venosus

right vitelline vein

The changes that normally occur shortly after birth include:
the umbilical vein becomes the ligamentum venosum
blood flow in the pulmonary arteries is reversed
thymus gland undergoes involution
the umbilical arteries become medial umbilical ligaments

the umbilical arteries become medial umbilical ligaments

The sinus venosus:
has a right horn which persists in the adult as the coronary sinus
has a left venous valve that develops into the valve of the coronary sinus
forms the smooth-walled portion of the adult right atrium
receives blood directly from the portal vein

forms the smooth-walled portion of the adult right atrium

Ostium secundum defect:
is characterized by a large opening between left and right atria
may be caused by excessive resorption of septum primum
may be caused by inadequate development of septum secundum
may be accompanied by intracardiac shunting of blood
all of the above are correct

all of the above are correct

At birth, increased pressure in the left atrium is directly caused by:
closure of the foramen ovale
cessation of placental blood flow
closure of the ductus venosus
closure of the ductus arteriosus

closure of the ductus arteriosus

The most common type of cardiac septal defect is:
muscular type ventricular septal defect, or VSD
secundum type atrial septal defect, or ASD
membranous type VSD
primum type ASD
sinus venosus

membranous type VSD

The crista terminalis is derived from:
right horn of the sinus venosus
left horn of the sinus venosus
primitive atrium
AV canal
right cusp of the valve of the sinus venosus

right cusp of the valve of the sinus venosus

The stage of lung development, 6 mos. to after birth, during which the respiratory epithelium becomes squamous and the capillary loops are intimately related to the epithelium is the:
glandular period
vascular period
alveolar period
canalicular period
acinar period

alveolar period

Pulmonary surfactant most likely begins to form in the human fetus at about _____ weeks.
16
20
28
32
34

28

The terminal sac or saccular stage of lung development is characterized by the appearance of:
secondary bronchi
Tertiary bronchi
respiratory bronchi
surfactant
mature alveoli

surfactant

The tracheoesophageal septum separates the:
laryngotracheal tube and nasopharynx
esophagus and nasopharynx
laryngotracheal tube and esophagus
laryngotracheal tube and oropharynx
esophagus and oropharynx

laryngotracheal tube and esophagus

The laryngotracheal diverticulum develops within the floor of the pharynx between arches:
I and II
II and III
III and IV
IV and VI
none of the above

IV and VI

The cloacal membrane is derived from:
ectoderm
endoderm
both
neither

both

The liver is a derivative of:
the embryonic foregut
the embryonic midgut
both
neither

the embryonic foregut

The spleen is a derivative of:
the embryonic foregut
the embryonic midgut
both
neither

neither
It develops from mesenchyme within the dorsal mesogastrium

In the digestive system:
endoderm forms the lining of the stomach and lung and the parenchymal cells of the liver
gut rotation and fusion of mesentery to the dorsal body wall makes the spleen retroperitoneal
the duodenum is supplied by both superior and inferior mesenteric artery
the inferior mesenteric artery is the axis for counterclockwise rotation of the midgut loop

endoderm forms the lining of the stomach and lung and the parenchymal cells of the liver

Gut rotations and subsequent fusion of mesentery to the dorsal body wall causes which of the following to assume a retroperitoneal position?
gall bladder
pancreas
spleen
jejunum

pancreas

In the formation of the pancreas:
a dorsal and ventral bud from the endoderm of the duodenum are the first indications of a pancreas
the ventral pancreatic bud degenerates
an annular pancreas forms if a portion of the dorsal bud rotates abnormally
insulin is not secreted during fetal life

a dorsal and ventral bud from the endoderm of the duodenum are the first indications of a pancreas

The yolk sac detaches from the gut by the end of the:
2nd week
5th week
3rd month
4th month
5th month

5th week

The terminal dilated part of the hindgut is called the:
cloaca
yolk stalk
allantois
cecum
coelom

cloaca

The allantois is derived from:
ectoderm
endoderm
both
neither

endoderm

The allantois is an endodermal outpouching of the yolk sac. Early on, it is attached to the hindgut, but when the urorectal septum divides the cloaca, it becomes associated with the urinary bladder and contributes to its development. The allantois forms the urachus and then the median umbilical ligament.

what develops from the intermediate mesoderm in response to induction by the ureteric bud?

kidneys

what is a remnant of the allantois?

median umbilical ligament

The ureteric bud appears as an outgrowth from the:
metanephric mass
lateral plate mesoderm
urogenital sinus
allantoic duct
mesonephric duct

mesonephric duct

Bilateral renal agenesis:
is due to an endocrine imbalance
is incompatible with life
results when the kidneys fail to migrate out of the pelvis
is due to the absence of a paramesonephric duct

is incompatible with life

In the urinary system:
the excretory units are outgrowths from collecting ducts
the bladder is a derivative of the urogenital sinus
the collecting ducts are derived from the metanephric blastema
a urachal fistula is a remnant of the cloaca

the bladder is a derivative of the urogenital sinus

The structure dividing the cloaca into two parts is the:
distal retention band
transverse septum
urogenital sinus
urorectal septum
cloacal membrane

urorectal septum

Horseshoe kidney:
involves splitting of the ureteric bud into a horseshoe shape
normally ascends to the L2 vertebral level
involves the persistence of the mesonephric kidney
results from fusion of the caudal poles of the kidneys

results from fusion of the caudal poles of the kidneys

Structures derived from the mesonephric ducts include the:
seminiferous tubules
ureter
prostatic urethra
ductus deferens

ductus deferens

The scrotum of the male develops from:
endoderm of urogenital sinus
urethral groove
urogenital folds
genital or labioscrotal swellings

genital or labioscrotal swellings

The penile urethra is derived from the:
urogenital sinus
pelvic part of the vesicourethral canal
phallic part of the vesicourethral canal
cloaca
mesonephric duct

urogenital sinus

The following structures are the derivatives of the primitive urogenital sinus EXCEPT:
most of the urinary bladder
male urethra
female urethra
upper part of vagina
vestibule of the vagina

upper part of vagina