Developmental Biology Exam Questions
With Correct Answers
The bicoid protein gradient results from: - answer✔the diffusion of bicoid protein across the
syncytial embryo
. Which of the following is true about maternal effect genes such as bicoid - answer✔embryo
maternal mRNA genotype is same as mother genotype
The bicoid gradient is not representative of morphogen gradients observed in - answer✔The
bicoid gradient is not representative of morphogen gradients observed in
How does the mother place bicoid and nanos mRNAs at opposing ends of the
drosophila oocyte? - answer✔bicoid mRNA is transported to the anterior end along
microtubules
Which of the following is true about dorsal-ventral patterning in the drosophila
oocyte? - answer✔SOG antagonizes Dpp signaling
Which of the following is NOT true about gap gene expression: - answer✔it may be inhibited
by pair-rule genes
Each stripe of pair-rule gene expression is activated by: - answer✔b. its own enhancer
c. transcriptional activators and repressors
e. b and c
Which of the following supports the position of Hunchback (Hb) upstream of the
gap gene Kruppel (Kr) and downstream of Bicoid (Bcd) during drosophila early
development? - answer✔all of the above
Which of these homeotic transformations may result from a Hox gene mutation? - answer✔arm
into leg
Which of these propositions is consistent with spatiotemporal colinearity of Hox
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genes? (hint: Hox gene number reflects order on chromosome) - answer✔c and d
c. hoxa1 is expressed before hoxa3
d. hoxa1 is expressed more anteriorly than hoxa3
Which of the following is NOT true about gastrulation? - answer✔c. mesoderm stays outside
Which of the following is true about gastrulation? - answer✔c. cells passing through the
blastopore first end up most anterior
Which of the following is NOT true about the blastopore? - answer✔its initial position
indicates the ventral side of the embryo
Which of the following is NOT true about embryonic tissues? - answer✔mesenchymal cells are
arranged as a sheet
Which of the following is NOT true about the cytoskeleton? - answer✔. microtubules growth
can be bidirectional
Which of the following is true? - answer✔radial cell-cell intercalations contribute to epiboly
Which of the following is true about specification of the germ layers? - answer✔Sox17
specifies the endoderm fate
Which of the following is true about specification of the dorsal-ventral axis in
the frog embryo? - answer✔B-catenin is a transcription factor that activates dorsal fates
Which of the following describe the requirements for Nieuwkoop center
formation: - answer✔a. nuclear B-catenin
b. VegT
Which of the following describe the requirements for Spemann organizer
formation: - answer✔a. nuclear B-catenin
c. reception of Nodal-related ligands (Vg1 and Xnr)
e. a and c
Vertebrate embryos develop following which of the following stage orders -
answer✔fertilization, cleavage, gastrulation, organogenesis
Which of the following statements describing the relationship between cell
commitment and cell totipotency is WRONG : - answer✔committment is an abrupt process that
takes place just prior to differentiation