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79 Cards in this Set

  • Front
  • Back
Causes of prematurity include:
a. multiple gestations
b. maternal hypertension (preeclampsia)
c. infection (chorioamnionitis)
d. all of the above
Common disorders of neonates with gestational ages 24-26 weeks include:
a. respiratory distress syndrome (RDS)
b. intracranial hemorrhage (IVH)
c. hypothermia
d. all of the above
Capacitation of the sperm:

a. occurs in the epididymis.
b. occurs in the fallopian tube.
c. occurs immediately after the acrosome reaction.
d. is important to block polyspermy.
Which of the following types of placentas is incompatible with dizygotic twins:

a. dichorionic diamnionic with separate discs.
b. dichorionic diamnionic with fused discs.
c. monochorionic monoamnionic with fused discs.
d. none of the above.
Destabilization of mitochondria by pro-apoptotic proteins does NOT involve:

a. release of cytochrome C into the cytoplasm
b. activation of caspase 9
c. activation of caspase 3, 6 and 7
d. release of cytochrome C into the nucleus
Which of these statements is true about the receptor mediated pathway of apoptosis:

a. does not involve the mitochondrial pathway
b. can be induced by TNF alpha
c. does not involve caspases
d. involves caspase 9.
We noted in lecture that all somites appear as epithelial balls (rosettes).

a. Until the epithelial to mesenchymal transition begins all somites carry the same positional information.
b. Until the epithelial to mesenchymal transition begins all somites can, if transplanted to thoracic levels give rise to ribs.
c. Before the epithelial to mesenchymal transition transplantation of thoracic somites to the cervical level takes on the phenotype of that cervical level.
d. Before the epithelial to mesenchymal transition transplantation of thoracic somites to the cervical level still give rise to ribs.
In vertebrates a segmental pattern is established in the trunk mesoderm which is the followed by homeotic transformation of each segment.

a. Underlying this transformation is the expression of “HOX” genes with each segment expressing a unique member of the hox family.
b. Underlying this transformation is the expression of an overlapping combinatorial pattern of “HOX” gene expression in a segment or series of segments.
c. Hox proteins encoded by hox genes are transmembrane receptors.
d. Hox proteins encoded by hox genes are Ca++ or Na+ channels.
In addition to the appropriate degree of elongation and phenotypic differentiation of, for example, digits vs. long bones these structures must also be patterned. In the case of digits of the upper limb we (primates) have thumbs that are very different from little fingers. Such patterning, using the hand or foot as an example, is produced by

a. Corticosteroids such as cortisol.
b. Nerve growth factor.
c. Secretions of the apical ectoderm ridge (AER) only.
d. none of the above.
BMP (bone morphogenetic protein) produced in the mesenchyme underlying the AER is (directly or indirectly)

a. inhibitory to the production of FGF4 in the AER.
b. inhibitory to the production of sonic hedgehog in the ZPA.
c. Is itself (or its production) inhibited by gremlin (GRE).
d. All of the above.
Exposure to which of the following during the first trimester is most likely to be teratogenic?

a. Thalidomide.
b. Tylenol.
c. Cocaine
d. An X-ray of the arm.
Which of the following has NOT been associated with birth defects?

a. Amniotic bands.
b. Mutations in the transcription factor PAX6.
c. Retin A (a vitamin A derivative).
d. Folic acid supplements.
The cells that produce testosterone in the fetal testis are:
leydig cells
serotollit cells
seminiferous tubules
rete testes
leydig cells
Merkkerian inhibitng substance in the fetal testis is produced by
serotoli cells
The effect of which one of the following moecules secreted by AER stimulates the ZPA cascade:

Retinoic Acid
When donor AER and recipient limb primordium are same age there will be:
full formation of skeletal elements
When AER is from older donor onto the younger limb primordium there will be:
full formation of skeletal elements
When AER is from younger donor onto the older limb primordium there will be:
distal skeletal elements only
The zone of proliferating activity of the forlimb would work equally as well as a replacement for the ZPA in the hindlimb.

The limb innervation:
a. arrivees before distinct muscle masses are formed
b. is guided to its termination by signals in part in the extracellulat space
c. pattern of distribution is altered by limb rotation
d. all of the above
D- all of the above
During limb development the mesenchyme begins to condese. It will then form:
a. a cartilage model of the bones in a proximal to distal direction over time
b. a cartilage model of the bones in a distal to proximal direction over time
c. bones directly without going through a cartilag emodel
d. all of the above
The skeletal elements of the limb are derived from the lateral plate mesoderm. The muscles of the limb are derived from the:
a. Lateral plate mesoderm
b. intermediate mesoderm
c. migratory cells from the somites
d. nueral crest
One of the main functions of the apical ectodermal ridge of the limb bud is to:
a. signal the mesenchyme to produce forelimb or hindlimb skeletal elements
b. secrete SHH
c. inhibit cell division in the progress zone
d. none of the above
none of the above
All of the following occur during capacitation EXCEPT:
a. sperm motility is activated
b. there is an influx of Na+ which is balanced by an efflux of H+
c. Ca+ uptake is increased
d. sperm lose cell surface glycoproteins
During the acrosome reaction in mamallian sperm:
a. sperm motility increases
b. the inner acrosomal membrane becomes the outer boundry of the sperm head
c. a protease is released by exocytosis
d. the sperm nucleus begins to decondense to form pronucleus
The initial binding btw mamammlian sperm and eggs:
a. involves egg surface integrins
b. is affected by pretreatment of the egg with N-linked glycohydrolases
c. involves high energy sugar intermediates (UDP-sugars)
d. invovles only one of the three zona pelluciaglycoproteins
As a result of sperm egg plasma membrane fusion:
a. cortical granule exocytosis is stimulated
b. the acrosomal reaction is completed
c. the zona pellucida is released
d. the block tp polyspermy is ended
Microvilli on the egg surface play an important role in incorporating the sperm during fertilization. Based upon their structure, which drug would you think would block the contribution of microvilli to incorporating the sperm into egg?
a. latrunculin, a microfilament inhibitor
b. colcemid, a MT inhibitor
c. puromycin, a protein synthesis inhibitor
d. tunicamycin, an inhibitor of the formation of N-glycosidic linkages
All the following are correct in formation of muscle tissue in the body EXCEPT:
a. all skeletal muscles in the trunk are derived from somites
b. limb musculature originates from the lateral plate mesoderm
c. smooth muscle tissue of the GI tract develops mainly form the splanchnic mesoderm
d. cardiac muscle develops from the splanchnic mesoderm surrounding the endothelial heart tube
The presomitic mesoderm (paraxial mesoderm before somites appear) carries positional information or is said to be pre-patterned. This is evidenced by:
a. retention of rib-bearing capability when thoracic paraxial presomitic mesoderm is transplanted to the cervical region
b. loss of rib-bearing capability when thoracic paraxial presomitic mesoderm is transplanted to the cervical region
c. loss of the ability to differentiate at all the following transposition to a different axial level
d. loss of the ability for sclerotome to form vertebrate but retention of the ability of myotome to make axial musculature appropriate for the original site (thoracic)
it can be demonstrated that the cranial (anterior) half of the somite is not identical to the caudal (posterior) half. The evidence includes:
a. onle the caudal (posterior) half contains a protein that repels axonal growth cones
b. only the cranial half secretes an attractive signal to guide motor axons from the spinal cord
c. only the cranial half gives rise to the vertebral column
d. only the posterior half gives rise to the axial muscles
if somites are removed from the thoracic region:
a. no nueral crest cells will migrate and hence no dorsal root ganglion cells will form in this region
b. no motor axons will grow out
c. neural crest cells destined to become sypathetic ganglion cells will migrate to the right place but will be an unsegmented continuum in the region missing somites
d. all of the above
e. none of the above
Somites are added at regular intervals. This regularity requires:
a. a molecular clock
b. signaling between Nothc and Delta
c. a wave of gene expression starting caudally and "moving" sotally
d. all of the above
e. none of the above
Signalling between Notch and Delta:
a. occurs when Notch protein is secreted by the signaling cell
b. involves the interaction of two transmembrane proteins
c. occurs when Delta protein is secreted by the signaling cell
d. occurs when Nothch protein is "presented" to Delta via binding to ECM elements
The endometrium is "receptive":
a. during its proliferative phase
b. beginging at the time of ovulation
c. largely due to the influence of human chorionic gonadotropin (hCG)
d. 6 days following ovulation
The cells of the blastocyst that adhere to the endometrial lining at implantation are:
a. inner cell mass
b. synctiotrophoblasts
c. cytotrohoblasts
d. hypoblast
The trophoblast secretes human chorionic gonadotropin (hCG), which :
a. opens the window of receptivity
b. maintains the corpus luteum
c. promotes rebuilding of the endometrium following menstruation
d. is the matrix metalloproteinase MMP
Decidualization refers to:
a. shedding of the trophoblast
b. the loss of the zona functionalis at menstruation
c. alterations in the stromal cells of the endometrium
d. the merging of the decidua capsularis with the decidua parietalis
During the stage of development in this picture the levels of oxygen in the placenta are:
a. low
b. high
Select the correct label fo structure at I:
a. outer cytotrophoblastic shell
b. layer of syncytiotrophoblas
c. chorionic plate
The leader at II indicates:
a. spaced filled with fetal blood
b. space filled with maternal blood
c. decidia
The leader at III indicates:
a. definite yolk sac
b. amnion
c. chorionic cavity
If you fertilized eggs that had been previousl injected with a Ca++ chelating agent to maintain intracellular Ca++ at low level, what effect would this have on fertilization?
a. none
b. fetilization would be inhibited b/c the sperm would not be able to bind to the egg
c. fertilization would be inhibited b/c the sperm would not be able to undergo the acrosome reaction
d. fertilization would not be inhibited b/c the sperm would not fuse with the egg
e. fertilization would proceed normally, but the cortical reaction would be inhibited resulting in polysermy
Fertilin AKA PH-30 is a heterodimeris sperm protein thought to participate in fusion of the egg and sperm membranes. One of the sub-units has homology to viral fusion proteins; the other contains a region of homology to disintegrins. How might a disintigrin work during fertilization:
a. disrupt the lipid bilayer allowing the other subunit to fuse the membranes together
b. would bind to sperm components after sperm-egg fusion and dispers them into the egg
c. bind to an integrin on the egg surface bringing the fusion protein subunit into proximity to the egg plasma
d. distrupt the egg integrin that normally prevents fertilization
All somites are present at the same time?

The ventromeial quadrant of the somite de-epithelizes and becomes mesenchymal. Thereafer:
a. selescted cells will migrate into the limbs and become limb skeleton
b. selected cells will migrate into the limbs and become muscle
c. selected cells will migrate ventromedially and differentiate into the ventral body
Not only do somites have regional spcification along the meidial lateral axis, but they are also specified along the cranial/caudal axis(within each somite). For the peripheral NS this specificatio ninto a cranial (anterior) and caudal (posterios) region:
a. results in the growth of motor axons being confined to the cranial region
b. in the migration of the neural crest cells that give rise to the dorsal root ganglia and sympathetic chain ganglia being restricted to the caudal region
c. has no particular influence on the PNS as it is prepatterned into segments
The skeleton of the limb orginates from ________ and the muscles come from the ___________.
paraxial mesoderm
The limb is an excellent place to study pattern formation. The outgrowth of the limb in a proximal to distal direction is:
a. intrisic to the mesenchyme that forms the skeltal elements
b. sequential, in that the humerous is laid down before the radius and ulna, etc
c. is independent of signaling centers in the limb itself
d. not any of the above
What would happen if the apical ectodermal ridge is removed just after the appearance of the wing (forelimb) bud?
You would get a truncated limb bud. How truncated the limb depends on how early you remove the AER. The earlier you remove it the more truncated it is.
When an ectpoic 2nd zone of polarizing activity is placed in the anterior most ascpect fo the forelimb it results in a complete mirror image duplication of the digits. Why?
ZPA secretes SHH which sets up a concentration gradient. It is established such that cells close to the ZPA have a high SHH and thus a posterior fate and cells far from the ZPA have alow SHH and thus an anterior fate. If you have 2 ZPA you get this sequence of digits" posterior-anterior-posterior" mirror-image
To maintain the zone of polarizing activity the AER must be present:
Cytochalasin D is an inhibitor of actin polymerization and is known to block mammalian fertilization. At which step would you expect cytochalasin to block fertilization:
a. sperm-egg binding
b. sperm motility through the zona pellucida
c. incorporation of the sperm into the egg after plasma memebrane fusion
d. fusion of sperm and egg plasma membranes
The barrier to species fertilization is due to:
a. differences in sperm fertilins
b. acrosin
c. ovoperoxidase
d. o-linked oligosaccharides in the zona pellucida
During compacitation the sperm acquires the ability to fertilize the egg. Of the processes that occur during capacitation, which one is the most important in promoting the initial binding of the sperm to the egg?
a. the change in the beat frquency of the sperm tail
b. the loss of glycoproteins from the sperm surface
c. the acrosome reaction
d. the uptake of Ca+ ions
After fusion of the sperm with the egg, the egg mounts a response that prevents additional sperm from entering the egg. Which process below is NOT involved in this block to polyspermy?
a. excocytosis of corticl granules
b. digestion of zona pellucida glycproteins
c. release of ovoperoxidase
d. endocytosis of egg integrins
e. the propagation of a wave of Ca around the egg
Competition experiments with isolated zona pellucida componetns were used to id the egg receptor fo rthe sperm. name the specific zona pellucida component id.
O-linked oligosaccharides on the ZPG III
The enbyro implants:
a. at the 16-cell stage
b. as a morula
c. as a blastula
d. as a gastrula
The cells that adhere to the endometrial lining are:
a. future ectoderm
b. future endoderm
c. cytotrophoblasts
d. syncytiotrophoblasts
The source of progesterone is:
a. uterine glands
b. endometrial epithelium
c. corpus luteum
d. trophoblast
The source of human chorionic gonadotroin is:
a. the inner cell mass
b. the trophoblast
c. the endometrium
d. the corpus luteum
Decidualization refers to:
a. the preparation fo the endometrium for implantation
b. the loss of the zona feunctionalis at menstrualization
c. the conversion of cytotrophoblasts to syncytiotrophoblasts
d. the merging of the decidua capsularis with the decidual parietalis
Which of the following zones of mesoderm will give rise to somites?
a. notochord
b. preshordal plate
c. paraxial mesoderm
d. intermediate mesoderm
e. lateral plate mesoderm
Which if the following give rise to a nucleus pulposus of an intervertebral disc?
a. notochord
b. prechordal plate
c. paraxial mesoderm
d. intermediate mesoderm
e. lateral plate mesoderm
One somite contribute to how many vertebrate?
a. 1
b. 0
c. 2
d. 3
The skeletal elements of the limbs and body wall are formed by mesenchyme that is derived from:
a. paraxial mesoderm
b. somatopleuric mesoderm
c. splanchnopleuric mesoderm
d. intermediate mesoderm
The dermatone component of a somite contributes to twhich of the following?
a. ventral dermis
b. dorsal dermis
c. dermis of the face
d. 'dermis of the limbs
The clock and wavefront model of somitogenesis is based on the hypothesis that a molecular clock is involved in this process. Which one of these two processes moves in the rostral/caudal direction?
the wavefront
In what part of the body do somitomeres NOT continue further development to become somites?
in the head region
A skeletal muscle is composed of striated muscle and a variety of CT elements. Provide the embryonic origins of the following:
a. striated muscle cells
b. CT in ventral body wall and limbs
c. dorsal muscles
d. CT for facial and neck region
a. paraxial mesoderm
b. lateral plate mesoderm
c. paraxial mesoderm
d. neural crest
Which of the following is NOT a feature of apoptotic cell death?
a) cytoplasmic blebbing b) cellular and nuclear pyknosis
c) cell and nuclear swelling d) DNA degradation by endonucleases
True or false: Caspases act via an active cysteine residue that selectively cleaves their cellular protein substrates after aspartyl residues.
BCL-2 is involved in all of the following EXCEPT:
a) maintaining the integrity of mitochondria
b) over-expression in B cell tumors
c) promotion of cell death d) activation of APAF-1
Which of the following is NOT a prominent death ligand or receptor?
a) TGF-beta1 b) TNFalpha
True or false: The process of cavitation is achieved by release from the ectodermal cells of a signal that promotes cell death of endodermal cells, except for those in contact with the basement membrane.
Which of the following is correct; during the formation of the proamniotic cavity:
a. a hollow tube forms b/c the endodermal cells undergo apoptosis
b. cells not in contact with the BL die
c. a signal from the BL leads to its own demise
d. uterine fluids, rich in oxygen and nutrients, do not reach the cells in the center of the blastocyst
All of the following statements are correct regarding promotion of programed cell death during formation of the digits, EXCEPT:
a. blocking BMP expression prevents seperation of the digits.
b. the mesoderm btw presumptive digits undergoes programmed cell death
c. random DNA degradation
d. the spithelium plays an important role in promoting expression of required signaling molecules and transcriotion factors
Included in the BCL2 family or proteins are members that:
a. destabilize mitochondrial integrity
b. block cell death by stabilizing mitochondria
c. promote cell death
d. all of the above
all of the above
The ultimate molecular killer in mitochondrial dependent apoptotis cell death is/are:
a. the family of caspases
b. membrane limited apoptotic bodies
c. mitochondrial toxins that cause mitochontrial disintegration
d. receptors for TNFa