BIO 529 S05
Exam II
Name______________________
ID #_______________________
1. Fill in the blanks with the best answer from the list provided. (1 pt each)
archenteron
bottle cells
induction
Noggin
determination
gastrulation
morphogen
autonomous
Hunchback
superficial
specification
holoblastic
telolecithal
hyalin
delamination
involution
ingression
vertebrate
polyspermy
notochord
Chordin
Disheveled
Goosecoid
-catenin
blastopore
blastula
homeotic selector
Serine protease
Wnt
deuterostome
TGF-
Animal hemisphere
cytokinesis
capacitation
Vegetal hemisphere
FGF
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
____________________
epiboly
gap genes
acrosome
cleavage
EGF receptor
GSK-3
Torso
Gurken
Bicoid
cephalic furrow
jelly layer
ventral furrow
meroblastic
BMP4
karyokinesis
Hedgehog
differentiation
Smad
Spemann’s organizer
Nieuwkoop center
fertilization cone
zona pellucida
Marginal zone
regulative development
cortical granule
mosaic development
mid-blastula transition
syncytial
segment polarity
mesenchyme
pair-rule
cumulus
gray crescent
Mitosis-promoting factor
invagination
vitelline envelope
Region surrounding the mammalian egg to which the sperm binds
Transcription factor activated by TGF- signaling
Process in which a sheet of cells migrates into the space of a gastrula
Protein present in gradient that initiates Drosophila anterior axis
formation
Region at the interface of the animal & vegetal poles
Tissue that induces neural tube formation
Transcription factor that is only expressed in the organizer
Type of patterning gene that determines segment identity in
Drosophila
Type of cell with loose association with surrounding tissue
Region of embryo that induces the organizer to form
Embryonic stage of rapid cell division without substantial growth
First structure formed by gastrulation in amphibian embryo
Internal movement of a cell sheet over an outer layer of cells
Molecule from cortical granules to which developing blastomeres
attach for support
Movement of outer epithelium to cover inner cell sheet
Structure that becomes moves away from the egg after fertilization
Wnt pathway molecule that is relocalized during cortical rotation
Molecule that specifies the ventral side of the amphibian embryo
Region of embryo with lower concentration of yolk.
Stage during which expression of the zygotic genome begins
1
BIO 529 S05
Exam II
Name______________________
ID #_______________________
For all remaining questions, you must show your work or explain your reasoning to receive
any partial credit.
2a. Describe what happens in the fast block to polyspermy in sea urchins. (8 pts)
b. Some researchers are interested in studying the consequences of sea urchin polyspermy.
Describe one method that can be used in the laboratory to overcome the fast block to
polyspermy. How does this work? (4 pts)
2
BIO 529 S05
Exam II
Name______________________
ID #_______________________
3. Classify the following organisms with respect to the following features. (10 pts)
Organism
Cleavage Type
Egg Type
Zebrafish
human
chicken
Drosophila
Ascidians
Cleavage Type is holoblastic or meroblastic
Egg Type is centrolecithal, isolecithal, mesolecithal, or telolecithal
4. In class, we discussed the formation of endoderm in both sea urchins and in tunicates. We
discovered that the same protein is ultimately responsible for endoderm formation in both
animals, but through very different mechanisms.
a. What is the protein responsible for endoderm formation in these animals? (2 pts)
b. Compare and contrast endoderm formation in these animals. Address whether endoderm
is derived by autonomous or conditional specification. If cell interactions are involved,
indicate what they are. (8 pts)
3
BIO 529 S05
Exam II
Name______________________
ID #_______________________
5. Beginning with development of the egg in the mother, describe at the molecular level how the
anterior and posterior axes of the Drosophila embryo are formed. Include the
asymmetrically distributed molecules that establish the axes, as well as the later molecules
that establish a reiterated pattern of segments in the embryo. Name all the classes of genes
that are required and their order of action. (16 pts)
4
BIO 529 S05
Exam II
Name______________________
ID #_______________________
6a. Using a diagram, draw where in the Xenopus embryo the Nieuwkoop center and Spemann’s
organizer will form. Be sure to include in your diagram the point of sperm entry, and animal
and vegetal poles. Also illustrate the distribution of the molecules that determine the position
of the Nieuwkoop center (you may sketch multiple embryos to indicate each separate
molecule, if needed). (10 pts)
b. If the Xenopus embryo were injected with a drug that increases the activity of GSK-3, what
would the developing embryo look like? What would this do at the molecular level to the
embryo? (4 pts)
c. An organizer and Nieuwkoop center are common features in vertebrate development. For
each vertebrate in the table, indicate the structures equivalent to the amphibian organizer and
Nieuwkoop center. (6 pts)
Animal
Amphibian
Mouse
Chicken
Zebrafish
Nieuwkoop center
Nieuwkoop center
Organizer
Spemann’s organizer
5
BIO 529 S05
Exam II
Name______________________
ID #_______________________
7. Describe the Spemann-Mangold experiment that demonstrated the existence of an “organizer”
in the amphibian embryo. Include information about the methodology of the experiment,
including the developmental stage of embryos, the results, and the interpretation of the
outcome. (12 pts)
6