Pregunta 1
Pregunta
Fertilization typically occurs in the:
Respuesta
-
ovary
-
uterus
-
ampulla of the oviduct
-
isthmus of the oviduct
-
vagina
Pregunta 2
Pregunta
The zona pellucida:
Respuesta
-
is located between the oocyte and granulosa cells
-
hardens to provide a block to polyspermy
-
prevents premature (ectopic) implantation
-
all of the above
-
none of the above
Pregunta 3
Pregunta
Where in the developing embryo is the mesoderm layer absent so that there is no separation bewteen the ectoderm and endoderm layers?
1. oral plate
2. cardiac plate
3. cecal plate
4. lateral plate
Respuesta
-
1 & 2
-
1 &3
-
2 & 3
-
2&4
-
1,2,&3
Pregunta 4
Pregunta
Within the trunk of the developing embryo, paraxial mesoderm breaks up into:
Respuesta
-
thin layers called the intermediate mesoderm
-
thick layers called the lateral plate
-
somitomeres consisting of somitomere components
-
somites consisting of sclerotome, dermatome, and myotome components
Pregunta 5
Pregunta
During development Meckel's cartilage is known to become a portion of the:
Respuesta
-
chondrocranium
-
neurocranium
-
mandible
-
maxilla
Pregunta 6
Pregunta
The first branchial arch gives rise to:
Pregunta 7
Pregunta
At the beginning of the blastocyst stage there is:
Respuesta
-
development of a fluid filled cavity called the amnion
-
formation of an inner cell mass which becomes the trophoblast
-
formation of an outer cell mass which becomes the embryoblast
-
all of the above
-
none of the above
Pregunta 8
Pregunta
At the earliest stage of development the primitive stomadeum is bounded by the (May/ may not be relevant for this exam):
Respuesta
-
maxillary and mandibular prominences
-
the frontonasal prominence and mandibular prominence
-
the frontonasal prominence and cardiac bulge
-
the median nasal prominences and mandibular process
-
the maxillary and median nasal prominences and mandibular process
Pregunta 9
Pregunta
The muscle of the gut wall is embryonically derived from:
Respuesta
-
sclerotome
-
myotome
-
dermatome
-
intermediate mesoderm
-
lateral plate mesoderm
Pregunta 10
Pregunta
The mesodermal layer of the embryo:
Pregunta 11
Pregunta
During development the amnion and yolk sac are in temporary communication. This opening is:
Respuesta
-
allantois canal
-
neurenteric canal
-
Caso's canal
-
umbilicus
-
reichert's membrane
Pregunta 12
Pregunta
Neural crest cells can form or become all of the following except:
Respuesta
-
bone
-
cartilage
-
myelin
-
neurons
-
olfactory sensory cells
Pregunta 13
Pregunta
Secretions of epithelial cells of the oviduct:
Respuesta
-
provide nutritional material for the conceptus
-
together with cilia establish an outward flow that inhibits bacterial migration toward the peritoneal cavity
-
produce a current that helps orient spermatozoa
-
all of the above
-
none of the above
Pregunta 14
Pregunta
Progression from the 2-cell stage to the morula is called:
Respuesta
-
implantation
-
neurulation
-
cleavage
-
gastrulation
-
insemination
Pregunta 15
Pregunta
Which of the following is incorrect regarding the notochord?
Respuesta
-
arises from a notochordal process which at first is a hollow tubular structure
-
is formed during gastrulation
-
arises from the primitive pit
-
divides the developing embryo into cephalic and caudal halves
-
lies along the long axis of the embryo
Pregunta 16
Pregunta
THe muscles of mastication arise from mesenchyme of the _________ branchial arch.
Respuesta
-
first
-
second
-
third
-
fourth-sixth
Pregunta 17
Pregunta
In the following list of events or stages, which of event would be third: Morula, Fertilization, Graffian follicle, Hatching, Implantation?
Respuesta
-
morula
-
fertilization
-
graafian follicle
-
hatching
-
implantation
Pregunta 18
Pregunta
Which of the following is a false statement?
Respuesta
-
the zona pellucida is a matrix layer between the follicular epithelium and oocyte
-
a function of zona pellucida is to prevent premature implantation
-
zona pellucida encircles the morula
-
zona pellucida is surrounded by granulosa cells
-
zona pellucida is removed immediately following fertilization
Pregunta 19
Pregunta
Transport of the ovum is facilitated by:
Respuesta
-
the activity of cilia in the uterine tube
-
peristalic contractions of the muscularis of the uterine tube
-
the presence of active flagella in cells of the corona radiata
-
all of the above
-
a & b
Pregunta 20
Pregunta
Meiosis is completed prior to ovulation.
Pregunta 21
Pregunta
The syncytiotrophoblast is derived from the outer cell mass while the cytotrophoblast is derived from cells of the inner cell mass.
Pregunta 22
Pregunta
Alveolar bone is formed from:
Respuesta
-
mesenchyme derived from somites
-
epithelium from the oral ectoderm
-
mesenchyme from the primitive streak
-
mesenchyme from notochord
-
none of the above
Pregunta 23
Pregunta
The folding of the embryo causes:
Respuesta
-
endoderm to be on the inside of the embryo
-
ectoderm to be on the inside of endoderm
-
endoderm to be on the outside of the mesoderm
-
mesoderm to be on the outside of the ectoderm
Pregunta 24
Pregunta
From which embryonic layer is mesoderm derived?
Respuesta
-
epiblast
-
hypoblast
-
endoderm
-
neuroectoderm
Pregunta 25
Pregunta
Hatching occurs:
Pregunta 26
Pregunta
Which of the following statements concerning prenatal development is correct?
Respuesta
-
most congenital malformations occur during the last prenatal week
-
maturation of existing structures occurs during the second to eighth week
-
initiation of embryonic layers occurs during the first week
-
the fetus is the structure present during embryonic period
Pregunta 27
Pregunta
The oral plate consists of:
Respuesta
-
embryonic endoderm, mesoderm, ectoderm
-
a circular area anterior to the notochord in which the endoderm is fused to the embryonic mesoderm
-
the cloacal membrane and the overlying amnion
-
endoderm of the roof of the yolk sac and embryonic ectoderm
-
the cardiogenic mesoderm and the neuroectoderm
Pregunta 28
Pregunta
The first brachial arch gives rise to:
Respuesta
-
muscles of mastication
-
maxillary teeth
-
mandibular teeth
-
malleus
-
all of the above
Pregunta 29
Pregunta
Somites form from:
Respuesta
-
ectomesenchyme
-
intermediate mesoderm
-
lateral plate mesoderm
-
paraxial mesoderm
Pregunta 30
Pregunta
Which of the following cells have migrated from the neuroectoderm and are the basis for future bone of the maxilla and mandible?
Respuesta
-
sclerotome
-
trophoblast
-
mesodermal
-
neural crest
-
endodermal
Pregunta 31
Pregunta
Embryologically the muscular wall of the gut arose from the:
Pregunta 32
Pregunta
The cells of the _______ will form the embryo proper.
Respuesta
-
inner cell mass
-
cyrotrophoblast
-
outer cell mass
-
syntiotrophoblast
Pregunta 33
Pregunta
At the beginning of the third week of development a thickening of ectoderm overlying the notochord indicates the start of:
Respuesta
-
cleavage
-
gastrulation
-
primitive streak stage
-
neurulation
-
somite formation
Pregunta 34
Pregunta
Prior to the formation of the primitive streak the amnion and blastocystic cavity (yolk sac) communicate via the neuroenteric canal.
Pregunta 35
Pregunta
Regarding the early embryo, which of the following is False?
Respuesta
-
the epiblast faces the amniotic cavity
-
the embryonic shield consists of 2 layers prior to the formation of the primitive streak
-
following gastrulation mesoderm fills all the space between the ectoderm and endoderm
-
the hypoblast cells are primitive endoderm
Pregunta 36
Pregunta
Which of the following is Incorrect regarding the notochord?
Respuesta
-
it arises from a notochordal process which at first is a hollow tubular structure
-
it is formed during gastrulation
-
arises from the primitive node
-
it extends from the primitive pit in a caudal direction
-
divides the developing embryo into right and left halves
Pregunta 37
Pregunta
Conceptus includes:
1. extraembryonic structures derived from the zygote
2. embryonic structures derived from the zygote
3. chorion
4. syncytiotrophoblast
Respuesta
-
1
-
1, 2, & 3
-
1 & 3
-
all of the above
-
none of the above
Pregunta 38
Pregunta
Down syndrome is known for:
Respuesta
-
trisomy of chromosome number 20
-
production of a monosomy situation
-
facial enlargement and lengthened palate
-
fissured tongue and delayed tooth eruption
Pregunta 39
Pregunta
Which of the following supports the primitive embryo and is directly derived from ectoderm alone?
Respuesta
-
notochord
-
prochordal plate
-
secondary yolk sac
-
cardiac plate
Pregunta 40
Pregunta
Which of the following syndromes occurs due to failure of neural crest cells to migrate?
Pregunta 41
Pregunta
The face develops in the human between:
Respuesta
-
6 and 10 days
-
10 and 22 days
-
12 and 22 days
-
24 and 38 days
Pregunta 42
Pregunta
Primitive oral cavity is called?
Respuesta
-
primitive choana
-
buccopharingeal membrane
-
stomatodeum
-
foregut
-
none of these
Pregunta 43
Pregunta
Proteins that bind to specific DNA sequences and regulate transfer of genetic information from DNA to mRNA are called:
Respuesta
-
growth factors
-
transcription factors
-
receptors
-
messengers