Developmental Biology

Front 1

1) In mammalian fertilization, the acrosomal reaction of sperm is initiated at…
A) The zona pellucida
B) The cumulus layer.
C) The oocyte plasma membrane.
D) vitelline envelope.
E) The jelly layer.

Back 1

A) The zona pellucida

Front 2

2) In sea urchin fertilization, the acrosomal reaction of sperm is initiated at…
A) The zona pellucida
B) The cumulus layer.
C) The oocyte plasma membrane.
D) vitelline envelope.
E) The jelly layer.

Back 2

E) The jelly layer.

Front 3

(3-4) True (A) or false (B) about fertilization:
3) Oocytes often complete meiosis after sperm entry.

Back 3

True

Front 4

4) Release of Ca++ from internal stores in the oocyte is involved in both the cortical granule reaction and activation of egg metabolism.

Back 4

True

Front 5

(5-7) Match the polypeptide with its function (each can be used only once).
5) Resact ...
A) A receptor protein found on the sea urchin oocyte that initiates species-specific fusion.
B) A glycoprotein in the zona pellucida that initiates the acrosomal reaction.
C) A receptor protein found on the mammalian oocyte that initiates sperm-egg fusion.
D) A polypeptide secreted by oocytes that acts as a chemoattractant for sperm.
E) An extracellular protein found on the sea urchin sperm acrosomal process that initiates species-specific fusion.

Back 5

D) A polypeptide secreted by oocytes that acts as a chemoattractant for sperm.

Front 6

6) ZP3...
A) A receptor protein found on the sea urchin oocyte that initiates species-specific fusion.
B) A glycoprotein in the zona pellucida that initiates the acrosomal reaction.
C) A receptor protein found on the mammalian oocyte that initiates sperm-egg fusion.
D) A polypeptide secreted by oocytes that acts as a chemoattractant for sperm.
E) An extracellular protein found on the sea urchin sperm acrosomal process that initiates species-specific fusion.

Back 6

B) A glycoprotein in the zona pellucida that initiates the acrosomal reaction.

Front 7

7) Bindin...
A) A receptor protein found on the sea urchin oocyte that initiates species-specific fusion.
B) A glycoprotein in the zona pellucida that initiates the acrosomal reaction.
C) A receptor protein found on the mammalian oocyte that initiates sperm-egg fusion.
D) A polypeptide secreted by oocytes that acts as a chemoattractant for sperm.
E) An extracellular protein found on the sea urchin sperm acrosomal process that initiates species-specific fusion.

Back 7

E) An extracellular protein found on the sea urchin sperm acrosomal process that initiates species-specific fusion.

Front 8

8) Which factors in addition to the haploid nucleus are contributed by the sperm?
A) Mitochondria.
B) Centrioles (microtubule organizing center).
C) mRNAs.
D) none.
E) A and C
F) B and C
G) A and B

Back 8

B) Centrioles (microtubule organizing center).

Front 9

9) Which of the following is/are NOT part of the slow block to polyspermy in sea urchin?
A) Release of proteases from the cortical granules.
B) A change in electrical potential across the oocyte plasma membrane.
C) Formation of the fertilization envelope.
D) Formation of the hyalin envelope.
E) All are part of the slow block.

Back 9

B) A change in electrical potential across the oocyte plasma membrane.

Front 10

10) You discover a chemical compound (a drug) that binds physically to sodium (Na+) channels in the sea urchin oocyte plasma membrane. When you treat oocytes with this compound and then fertilize the oocytes, you note that polyspermy results. Based on this information, what is the most plausible (likely) effect of the drug?
A) Blocks release of cortical granules.
B) Binds to the sodium channels and prevents them from opening.
C) Binds to sodium channels and keeps them open at all times.
D) Blocks completion of oocyte meiosis.

Back 10

B) Binds to the sodium channels and prevents them from opening.

Front 11

(11-14) True (A) or False (B) about cells in early cleavage phase:
11) Lack of G phases.
12) Asynchronous cell division.
13) Rapid cell division.
14) Much cell movement.

Back 11

11. True
12. False
13. True
14. False

Front 12

(15-17) True (A) or false (B) about the mid-blastula transition:
15) Embryonic transcription begins.
16) Synchronous cell divisions.
17) G phases added to cell cycle.

Back 12

15. True
16. False
17. True

Front 13

18) Which of the following treatments of a sea urchin blastula would result in failure to specify skeletogenic micromeres?
A) Blocking nuclear accumulation of beta-catenin.
B) RNA-mediated interference (RNAi) of beta-catenin.
C) LiCl treatment to force beta-catenin to the nuclei of all cells.
D) A and B.
E) B and C.

Back 13

D) A and B.

Front 14

19) What happens when vegetal skeletogenic micromere cells are transplanted to the animal pole of a sea urchin embryo?
A) The transplanted skeletogenic micromere cells change fate to become ectodermal.
B) The transplanted skeletogenic micromere cells epibolize the embryo.
C) Normal development.
D) The animal pole cells are induced to become mesodermal and endodermal.
E) The animal pole cells are induced to become ectodermal.

Back 14

D) The animal pole cells are induced to become mesodermal and endodermal.

Front 15

(20-23). Which gastrulation movements are used by the following cells in sea urchin gastrulation?
20) Initial bending of the vegetal plate.
A) Epiboly
B) Invagination.
C) Involution.
D) Ingression.
E) delamination.
F) Convergent extension.

Back 15

B) Invagination.

Front 16

21) Vegetal plate primary mesenchyme cells.
A) Epiboly
B) Invagination.
C) Involution.
D) Ingression.
E) delamination.
F) Convergent extension.

Back 16

D) Ingression.

Front 17

22) Progression of the archenteron toward the animal pole after initial bending.
A) Epiboly
B) Invagination.
C) Involution.
D) Ingression.
E) delamination.
F) Convergent extension.

Back 17

F) Convergent extension.

Front 18

23) Animal pole ectodermal cells.
A) Epiboly
B) Invagination.
C) Involution.
D) Ingression.
E) delamination.
F) Convergent extension.

Back 18

A) Epiboly

Front 19

(24-27) In C. elegans, would ABp fates be induced (A) or not induced (B) by P2 in the following blastomere recombination experiments.
24) A wild-type P2 cell placed in contact with a apx-1/Delta mutant AB cell.

Back 19

A - be induced

Front 20

25) A wild-type P2 cell placed next to but not in contact with a glp-1/Notch mutant AB cell.

Back 20

B - not induced

Front 21

26) An apx-1/Delta mutant P2 cell placed in contact with a wild-type AB cell.

Back 21

B - not induced

Front 22

27) A wild-type P2 cell placed in contact with a mom-5/frizzled mutant AB cell.

Back 22

A - be induced

Front 23

28) The C. elegans AB blastomere divides to produce an anterior and a posterior daughter, both of which can be induced by P2 to express ABp cell fates. This experiment illustrates:
A) That P2 cell fate determination is autonomous.
B) That AB daughter cell fate determination is autonomous.
C) That P2 cell fate determination is non-autonomous.
D) The both AB daughter cells are an equivalence group.

Back 23

D) The both AB daughter cells are an equivalence group.

Front 24

32) The early cleavages (1-13) in Drosophila (fruit fly) involve:
A) Karyokinesis.
B) Cytokinesis.
C) Cytokinesis and karyokinesis.

Back 24

A) Karyokinesis.

Front 25

(33-37) When mutant, which group of Drosophila genes causes the following defects in development?
33) An embryo missing no segments, but the segments have no anterior-posterior differentiation.
A) Gap genes
B) Segment polarity genes
C) Maternal effect genes
D) Pair-rule genes
E) Homeotic genes

Back 25

B) Segment polarity genes

Front 26

34) An embryo missing each odd segment.
A) Gap genes
B) Segment polarity genes
C) Maternal effect genes
D) Pair-rule genes
E) Homeotic genes

Back 26

D) Pair-rule genes

Front 27

35) An embryo missing multiple contiguous segments in the middle.
A) Gap genes
B) Segment polarity genes
C) Maternal effect genes
D) Pair-rule genes
E) Homeotic genes

Back 27

A) Gap genes

Front 28

36) An embryo lacking all posterior abdominal segments.
A) Gap genes
B) Segment polarity genes
C) Maternal effect genes
D) Pair-rule genes
E) Homeotic genes

Back 28

C) Maternal effect genes

Front 29

37) An embryo with entire segments transformed to other segmental fates.
A) Gap genes
B) Segment polarity genes
C) Maternal effect genes
D) Pair-rule genes
E) Homeotic genes

Back 29

E) Homeotic genes

Front 30

(42-46) Would the following experiments with the amphibian frog Xenopus result in one dorsal embryonic axis (A), twinning of the dorsal embryonic axis (B), or no dorsal embryonic axis (a bellypiece) (C)?
42) Blockage of cortical rotation by UV irraditation.

Back 30

C - no dorsal embryonic axis (a bellypiece)

Front 31

43) Transplantation of a dorsal blastopore lip opposite the site of the Nieuwkoop center in the marginal zone.

Back 31

B - twinning of the dorsal embryonic axis

Front 32

44) Blockage of cortical rotation by UV irraditation and placement of a dorsal blastopore lip from a different embryo on the marginal zone.

Back 32

A - one dorsal embryonic axis

Front 33

45) Blockage of cortical rotation by UV irraditation followed by injection into the marginal zone of a mutant beta-catenin protein that always accumulates in the nucleus.

Back 33

A - one dorsal embryonic axis

Front 34

46) Treating the blastula to block nuclear accumulation of beta-catenin.

Back 34

C - no dorsal embryonic axis (a bellypiece)

Front 35

47) The Nieuwkoop Center is formed by which of the following?
A) Maternally-supplied -catenin activity localized to the future dorsal side of the embryo.
B) A mesoderm-inducing TGF/BMPsignal from vegetal cells.
C) An epidermal-inducing TGF/BMP signal from future ventral cells.
D) Blockage of ventral TGF/BMPand Wnt signals by the Organizer.
E) A and B.
F) A and D.

Back 35

E) A and B.

Front 36

48) The Xenopus dorsal blastopore lip organizer acts by which of the following?
A) Inducing dorsal cells using TGFBMP signaling.
B) Blocking TGF/BMP signaling from vegetal cells.
C) Blocking Wnt signaling from ventral cells.
D) Inducing dorsal cells using Wnt signaling.
E) A and D
F) B and C.

Back 36

F) B and C.

Front 37

(49-50). Fill in the blank. During Xenopus gastrulation, cells from the dorsal blastopore lip that form the pharyngeal endoderm and prechordal plate mesoderm induce anterior structures by inhibiting (49), and cells from the DBL that form notochordal mesoderm induce posterior structures by inhibiting (50).
A) BMPs
B) Wnts
C) Wnts and BMPs

Back 37

49. C) Wnts and BMPs
50. A) BMPs

Front 38

(29-31) In the experiments with C. elegans PAR proteins and mutants below, which experimental result best illustrates the following conclusions?
29) PAR-3 restricts PAR-2 to the posterior cortex.
30) PAR-1 is downstream of PAR-2 (PAR-1 does not affect posterior PAR-2 localization).
31) PAR-2 is required for PAR-1 localization to the posterior cortex.

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Back 38

29. H)
30. D)
31. E)

Front 39

(38-41) As diagrammed below, Hunchback and Caudal protein was detected by antibody staining in embryos of different mutants. Which experiment best illustrates the following conclusions?
38) Bicoid represses anterior Caudal translation

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Back 39

F

Front 40

39) Caudal translation is normally restricted to the posterior.

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Back 40

B

Front 41

40) Bicoid represses posterior Hunchback translation.

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Back 41

G

Front 42

41) Nanos represses posterior Hunchback translation.

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Back 42

C