BIO 529 S05
Exam III
Name______________________
ID #_______________________
1. Fill in the blanks with the best answer from the list provided. Words may be used more than
once. (1 pt each)
estrogen
Mullerian duct
notochord
uterus
Sry
aromatase
hermaphrodite
Hox genes
neural crest
testosterone
telencephalon
metencephalon
dendrite
spinous layer
cornified layer
neurotrophin
limb bud
amniocentesis
ephrin
dihydrotestosterone
Leydig cells
primary sex cords
cortical sex cords
oviduct
chordamesoderm
doublesex
neural plate
neural groove
endocrine disruptor
diencephalon
myelencephalon
axon
basal layer
epididymus
autopod
limb field
In vitro fertilization
netrin
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Wolffian duct
thecal cells
organizer
vas deferens
teratogen
Sex-lethal
numerator proteins
neural tube
neural folds
atrazine
transformer
glia
growth cone
keratin
melanocyte
stylopod
progress zone
positional cloning
semaphorin
Mullerian inhibitory substance
granulosa cells
Sox9
marginal zone
intermediate mesoderm
Sertoli cells
denominator proteins
oligodendrocyte
primary neurulation
secondary neurulation
mesencephalon
intermediate zone
ventricular zone
granular layer
Schwann
zeugopod
apical ectodermal ridge
chorionic villus sampling
zone of polarizing activity
The most distal segment of the tetrapod limb
Outer layer of skin, comprised of dead cells
The epithelial layer of the progress zone
Actively dividing layer of the spinal cord
Cells that often serve to guide migration neurons
A diffusible axon guidance molecule that forms a gradient
Cells responsible for production of Mullerian inhibitory substance
Sex determination genes in Drosophila that encode proteins which
influence alternative splicing of mRNA
Part of the brain associated with olfaction
Part of the brain associated with vision
Substance or condition that causes non-heritable birth defects
Epidermal layer that is actively dividing
The tip of an extending axon
Method to collect cells from placenta to genetically analyze embryo
Substance that causes regression of the Wolffian duct
Cells of the testes that are derived from the mesenchyme
Specific compound that stimulates aromatase activity
Compound required for proper development of the prostate and penis
Female equivalent of Sertoli cells
Location where embryo is introduced after in vitro fertilization
Location where embryo is introduced after ZIFT
Gonadal region into which the female germ cells migrate
1
BIO 529 S05
Exam III
Name______________________
ID #_______________________
For all remaining questions, you must show your work or explain your reasoning to receive
any partial credit.
2a. Name two different types of viruses that have been utilized for human gene therapy trials. (3
pts)
b. Explain at least two problems that have been encountered using these viral vectors. (4 pts)
3a. Label each layer or structure indicated by a box in the diagram of epidermis below. (8 pts)
b. What cell type would you find directly under the basal lamina? (2 pts)
2
BIO 529 S05
Exam III
Name______________________
ID #_______________________
4a. Name the two actively dividing layers of neuronal stem cells in the cerebellum. (3 pts)
b. What is the signaling molecule that maintains the outer proliferative layer of the
cerebellum and what cell layer produces that molecule? (4 pts)
5. Name the four populations of neural crest cells and one tissue that comes from each (8 pts)
6. Based on your knowledge of sex determination in flies and mammals, fill in the table below
to indicate the expected outward sexual appearance (phenotype) for each situation indicated.
Phenotypes you may choose are: male, female, or intersex. (15 pts)
Genotype
XY with constitutively activated Sex lethal gene
XXY human
XXY fly
XXY fly triploid for all autosomes
XXY with deletion of Sry gene
XXY with normal Sry gene
XX with homozygous deletion of transformer gene
XY fly with deletion of several numerator genes
XY fly with deletion of several denominator genes
XX with homozygous deletion of androgen receptor
XY with homozygous deletion of androgen receptor
XX with constitutively active FGF9 gene
XX with duplication of Sox9 gene
XX with homozygous deletion of Sox9 gene
XY with homozygous deletion of Sf1 gene
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Phenotype
BIO 529 S05
Exam III
Name______________________
ID #_______________________
7a. In the assigned reading from Riddle et al. (Cell paper from 1993), the authors used
misexpression of Shh to suggest that it could be the molecule responsible for the properties
of the ZPA. This was most clearly demonstrated by the implantation of cells expressing Shh
into the developing limb. Where in the limb were the cells implanted and what was the
outcome of the experiment? (4 pts)
b. Based on the results described above and the model presented by the authors, what would
have been the expected result from loss of Shh in the developing limb? (2 pts)
c. In the second assigned reading (Litingtung et al., from Nature 2002), the actual results of
the loss of Shh in the limb were reported. What was the phenotype? (2 pts)
d. In the Nature paper, they also looked at loss of the Ci homologue, Gli3. What was the
expected phenotype of loss of Gli3 in the developing limb? What was the actual phenotype?
How are these results explained? (6 pts)
4
BIO 529 S05
Exam III
Name______________________
ID #_______________________
8. Based on your knowledge of tissue interactions during limb development, predict the outcome
of the following surgical experiments in chick embryos. For each, be sure to indicate all limb
segments that would be produced, whether each is wing or leg, and indicate any altered
polarities of the tissue. (14 pts)
a. The mesoderm underlying the early wing bud is transplanted to replace the mesoderm of
the leg bud after production of the stylopod.
b. The ectoderm of the early wing bud is transplanted to replace the ectoderm of the leg bud
after production of the stylopod.
c. The tissue at the posterior of the early wing bud is removed and replaced with tissue from
the anterior of a different early wing bud.
d. The tissue at the anterior of the early wing bud is removed and replaced with tissue from
the posterior of a different early wing bud.
e. The mesoderm and ectoderm at the tip of a wing bud after production of the zeugopod is
transplanted to replace the mesoderm and ectoderm at the tip of a leg bud after
production of the stylopod.
f. The ectoderm tip of a wing bud after production of the zeugopod is added to the tip of a
leg bud after production of the stylopod.
g. The mesooderm underlying the wing bud is removed after production of the stylopod and
replaced with mesoderm from a leg bud after production of the zeugopod.
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BIO 529 S05
Exam III
Name______________________
ID #_______________________
9. Explain how the X:A ratio in Drosophila leads to the differential activation of a target
gene that will distinguish male from female. Be sure to include a description of the
molecular “measurement” of X:A ratio, how this molecularly initiates sex determination,
the identity of the target of X:A ratio regulation, and how that gene then distinguishes
male from female. If in doubt, provide more information rather than less. (10 pts)
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