#Question id: 7282
#Unit 5. Developmental Biology
In humans, neural tube closure defects occur in about 1 in every 1000 live births. Failure to close the neural tube can result from both genetic and environmental causes. A recent report has demonstrated that zinc deficiency disrupts neural tube closure by:
#Question id: 7281
#Unit 5. Developmental Biology
Evolutionary conservation of homeotic gene organization and transcriptional
expression in fruit flies and mice is seen in the similarity between the Hom-C
cluster on Drosophila chromosome 3 and the four Hox gene clusters in the mouse
genome.
According to this figure, Which of the following statement is correct?
#Question id: 7280
#Unit 5. Developmental Biology
In
drosophila, Physical forces drive invagination of the ventral furrow. Following
statements regarding to this process:
A. The cellularized blastoderm will begin
to activate higher levels of myosin in the cells at the ventral midline and
preferentially at their apical surface.
B. Epithelial adhesions paired with
differential activation of dynein and tissue geometry create mechanical
constraints that affect the orientation of actomyosin meshworks.
C. The A/P oriented arrays of myosin in the
cells at the ventral midline generate tension along the anterior-posterior
axis.
D. The combination of tissue geometry and
tension of these anterior-to-posterior meshworks cause the tissue to fold
outward at a right angle to the anterior-posterior axis, creating a long and
narrow ventral furrow.
Which of the following statements are incorrect?
#Question id: 7279
#Unit 5. Developmental Biology
X chromosome number alone is the primary sex determinant in normal drosophila because:
#Question id: 7278
#Unit 5. Developmental Biology
The following demonstrates the blastocoel formation in the mammals. Which of the following statement is correct?
#Question id: 7277
#Unit 5. Developmental Biology
According to this model, Which of the following statements are correct?