Download 2009 Exam 3

NAME _____________________________
BIOLOGY 205/SECTION 7
DEVELOPMENT- LILJEGREN
Third Examination – April 2, 2009
Please put your name at the top of each page. Read each question carefully before
answering- i.e. read the instructions. Be as specific as possible, while respecting the
amount of space allotted for each answer. No regrades for exams done in pencil.
1.) (4 pts) Name the key biological processes that generate each of the following
molecules, and specify the starting molecules:
______
RNA
_______
protein
2.) (5 pts) We talked about rules of evidence in Developmental Biology. Why do
correlative experiments provide the weakest evidence for figuring out a gene’s function?
______________________________________________________________________
What type of evidence do each of the following experiments or findings represent?
____________ Using a fibronectin competitor to block frog gastrulation
_______________ Observing that the blastopore always forms 180º from the site of
sperm entry
_______________ Finding that the blastopore forms next to the site of sperm entry in
experimentally rotated eggs
3.) (3 pts) The size of a human skin cell compared to that of a human egg cell is like
which of the following relationships: (more than one answer may be correct)
Write letter(s) here _________
(A) Size of frog egg compared to a snake egg
(B) Size of snake egg compared to a frog egg
(C) Length of the average gene (unwound) to the diameter of the average protein
(D) Size of fruit fly genome compared to mouse genome
(E) Size of mouse genome compared to fruit fly genome
(F) Diameter of the average protein to the length of the average gene (unwound)
4.) (4 pts) Order the following events in human development from the earliest to the
latest.
(A) Compaction
(E) Implantation in the uterus
(B) Gastrulation
(F) Formation of blastocyst
(C) Sperm formation begins
(G) First differentiation event
(D) Oocyte formation begins
(H) Fusion of egg and sperm
earliest ___<____<____<____<____<____<____<____ latest
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NAME _____________________________
5.) (2 pts) If an egg is experimentally manipulated so that it has double the amount of
cytoplasm compared to a normal egg, how many cell divisions would you expect for an
organism that normally undergoes four cell divisions before the mid-blastula transition?
(A)
(B)
(C)
(D)
Three
Four
Five
Eight
Write letter here ______
Explain in terms of the N/C ratio. __________________________________________
_______________________________________________________________________
6.) (2 pts) Each germ layer contributes to specific organs within our bodies. Which of
the following are correct?
Write letter(s) here _______
(A)
(B)
(C)
(D)
The
The
The
The
ectoderm gives rise to the brain
mesoderm gives rise to the lungs
endoderm gives rise to the gonads
ectoderm gives rise to the bones
7.) (4 pts) We’ve talked about the key contributions of several scientists to our
understanding of development. Match the names of the following scientists to their
respective discoveries. Some names will not be used as answers.
(A) Pieter Nieuwkoop
(D) William Harvey
(B) Hilde Mangold
(E) Wilhelm Roux
(C) Karl Ernst von Baer
(F) Hans Driesch
____ Cells can adjust their fates based on interaction with their neighbors.
____ Transplantation of the dorsal blastopore lip can induce formation of a second body
axis.
____ “Ex ovo omnia”
____ Dorsal vegetal cells can induce formation of the “organizer”
8.) (2 pts) Drosophila nurse cells and follicle cells provide support to the developing
oocyte. Which of the following are correct statements?
Write letter(s) here _______
(A) Nurse cells form an epithelium that surrounds the egg.
(B) Follicle cells produce nutrients that are pumped into the oocyte via gap junctions.
(C) Nurse cells produce mRNAs that are pumped into the oocyte via gap junctions.
(D) Follicle cells produce nutrients that are delivered into the oocyte via cytoplasmic
bridges.
(E) Follicle cells are mitotic sisters of the oocyte, and are derived from the germline.
(F) Nurse cells are meiotic sisters of the oocyte, and are derived from the germline.
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NAME _____________________________
9.) (18 pts) Mark each of the following questions as T or F and for any that is/are
false, indicate briefly why in the space below.
a. T
F
During cleavage, the embryo rapidly increases in size.
______________________________________________________________________
b. T F When Xenopus animal pole cells are cultured with vegetal pole cells, the
vegetal pole cells are induced to make mesoderm.
______________________________________________________________________
c. T
F
All cell types express the same proteins.
______________________________________________________________________
d. T
F
Exocytosis of the acrosomal vesicle propels the sperm toward the egg.
_____________________________________________________________________
e. T F In worms, the PAR-2 protein is asymmetrically localized during the first cell
division.
_____________________________________________________________________
f. T F Injection of Noggin mRNA into UV-irradiated frog eggs is able to rescue
formation of ventral structures.
_____________________________________________________________________
g. T F
kinase.
Activation of the epithelial Na+ channel (ENaC) is controlled by a protein
_____________________________________________________________________
h. T
F
Proto-oncogenes often play roles in normal cell growth or cell division.
_____________________________________________________________________
i. T F
cancer.
Gain-of-function mutations that activate a tumor suppressor gene can lead to
_____________________________________________________________________
10.) (6 pts) For each protein below, indicate which of the following categories
best describes its job in the cell where its expressed:
(Categories may be used more than once or not at all.)
a.
b.
c.
d.
Membrane-bound signal
Transcription factor
Secreted signal
Transmembrane receptor
e.
f.
g.
h.
Cytoskeletal protein
Cell adhesion protein
Ion channel protein
Protein kinase
Resact _________
CFTR __________
Wingless __________
Bindin ___________
E-cadherin __________
Actin __________
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NAME _____________________________
11.) (2 pts) Through a famous transplantation experiment, it was discovered that
transplantation of a region called “Hensen’s node” from a quail embryo to a chick
embryo resulted in the formation of two body axes in the chick embryo. Why did this
experiment demonstrate that this region can be considered an organizer?
(A)
(B)
(C)
(D)
Write letter here _______
Quail cells participate in forming the second body axis
Quail cells participate in forming the original axis
Chick cells participate in forming the original axis
Chick cells participate in forming the second body axis
12.) (8 pts) Draw pictures and describe in order from earliest to latest any TWO of the
first four cell movements that occur during sea urchin gastrulation. Draw/describe what
happens, specify the type of cell movement each event represents, the identity of
the cells, and which germ layer they become part of.
any two of the following four--
13.) (4 pts) Draw pictures and describe ONE of the types of cell movements that occur
during gastrulation in frogs but not in sea urchins. Draw/describe what happens during
this event, specify the type of cell movement, the identity of the cells, and which
germ layer they become part of.
Either of the two following—
14.) (3 pts) During human gastrulation, epiblast cells from the inner cell mass move
through the primitive streak. What type(s) of cell movements do these cells undergo
and what is the first germ layer that they contribute to?
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NAME _____________________________
15.) (4 pts) Molting is initiated by pulses of ________________ in an insect’s “blood”. If
this molecule is present and ___________ produced by the ______________ is present
at high levels, the insect will
____________________________________________________.
16.) (2 pts) A scientist transplants dorsal vegetal cells from a donor embryo to the
ventral side of a host embryo. What would you expect to happen if cells of the host
embryo exhibited regulative development and cells of the donor embryo exhibited
mosaic development?
Write letter(s) here ________
(A) The host embryo gastrulates normally with one head and body axis.
(B) The host embryo does not gastrulate and forms a ventral ‘belly piece’ with no head
or body axis.
(C) The host embryo gastrulates at two spots, forms a secondary body axis, and
develops two heads.
(D) The donor embryo gastrulates normally with one head and body axis.
(E) The donor embryo does not gastrulate and forms a ventral ‘belly piece’ with no head
or body axis.
(F) The donor embryo gastrulates at two spots, forms a secondary body axis, and
develops two heads.
17.) (3 pts) In fly eggs, the embryo’s dorsal/ventral axis is established by signaling
between the oocyte and surrounding follicle cells. Which of the following would you
expect to happen if scientists engineered a fly egg with uniformly localized Pipe protein
in the surrounding follicle cells? Write letter(s) here _____________
(A) The embryo would develop normally
(B) A dorsalized embryo would develop
(C) A ventralized embryo would develop
(D) The Torpedo receptor would be synthesized in all follicle cells
(E) The Torpedo receptor would be synthesized only in ventral follicle cells
(F) The Torpedo receptor would be synthesized only in dorsal follicle cells.
(G) The Torpedo receptor would not be synthesized in any follicle cells.
(H) Dorsal would enter both dorsal and ventral nuclei of the developing embryo,
resulting in all cells of the embryo becoming specified as dorsal cells.
(I) Dorsal would enter both dorsal and ventral nuclei of the developing embryo, resulting
in all cells of the embryo becoming specified as ventral cells.
(J) Dorsal would not enter any nuclei of the developing embryo, resulting in all cells of
the embryo becoming specified as dorsal cells.
(K) Dorsal would not enter any nuclei of the developing embryo, resulting in all cells of
the embryo becoming specified as ventral cells.
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NAME _____________________________
18.) (1 pt) Which of the following would you expect to happen if scientists engineered a
a fly egg with uniformly localized Pipe protein in the surrounding follicle cells in an egg
which was maternally-deficient for the Torpedo receptor?
(A) The embryo would develop normally
(B) A dorsalized embryo would develop
(C) A ventralized embryo would develop
Write letter(s) here ____________
19.) (2 pts) What model organism was used to demonstrate that the Splunc1 protein
was sufficient to inhibit conductance through the epithelial Na+ channel (ENaC)?
(A)
(B)
(C)
(D)
(E)
Arabidopsis
Xenopus
C. elegans
Drosophila
Mouse
Write letter here ____________
20.) (2 pts) Cystic fibrosis patients have trouble breathing because of a thick mucus
layer coating their lungs and severely reduced airway surface liquid (ASL) volume. The
Splunc1 protein was demonstrated to regulate ASL volume by which of the following
experiments?
Write letter here ___________
(A)
(B)
(C)
(D)
(E)
(F)
Human Splunc1 knockout bronchial cell cultures were found to have reduced
ASL height compared to normal bronchial cell cultures.
Human Splunc1 knockout bronchial cell cultures were found to have increased
ASL height compared to normal bronchial cell cultures.
Splunc1 knockout mice were found to have increased ASL height compared to
wildtype mice.
Splunc1 knockout mice were found to have reduced ASL height compared to
wildtype mice.
Wildtype mice treated with a Splunc1 inhibitor were found to have reduced ASL
height compared to control mice.
Wildtype mice treated with a Splunc1 inhibitor were found to have increased
ASL height compared to control mice.
21.) (3 pts) Under which of the following conditions can an oncogene be activated?
(A)
(B)
(C)
(D)
(E)
(F)
Write letter(s) here ____________
A new gain-of-function mutation occurs
A new loss-of-function mutation occurs
It is duplicated, so one more copy of the gene is present
It is deleted, so one less copy of the gene is present
A chromosomal rearrangement results in decreased expression
A chromosomal rearrangement results in increased expression
22.) (2 pts) Why is p53 normally able to prevent formation of tumors?
___________________________________________________________________
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NAME _____________________________
23.) (4 pts) Which of the following proteins are well-known for their ability to become
oncogenes or to suppress tumors? Label the oncogenes as O, tumor suppressors as TS,
and neither as N.
_____ Rb
____ Roy _____ Ras _____ Myc
24.) (10 pts) Mark each of the following questions as T or F and for any that is/are
false, indicate briefly why in the space below.
a. T F Dicty cells with a loss-of-function mutation in gp150 form smaller slugs and
fruiting bodies than wildtype.
____________________________________________________________________
b. T
F
In flies, the cell cycle is much shorter before the mid-blastula transition.
_____________________________________________________________________
c. T F
gland.
After puberty, monthly surges of LH and estrogen are produced by the pituitary
_____________________________________________________________________
d. T
F
Sperm can’t fuse to an egg when it has a negative membrane potential.
_____________________________________________________________________
e. T
F
In sea urchin, the cleavage plane forms perpendicular to the contractile ring.
_____________________________________________________________________
I certify that I have performed my work on this examination in full conformity
with the provisions of the Honor Code.
Signature __________________________________
Extra credit.) (1 pt) What was one of the early misconceptions about sperm?
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