In a haploid organism, lethal alleles would be expected to:

#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: 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: 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: 7283

#Unit 5. Developmental Biology

The Drosophila orthodenticle gene and the vertebrate Otx genes are homologous and provide a good example of the conservation of gene function during evolution. Which of the following statement is correct regarding to the expression of gene expression.

#Question id: 7284

#Unit 5. Developmental Biology

Choose the correct match.

#Question id: 7285

#Unit 5. Developmental Biology

During xenopus gastrulation, C3a functions as a short-range chemoattractant to guide the radial intercalation movements of cells. If Knockdown of C3a with antisense morpholinos results: