Following statements are regarding to gap junctions.

i. Vertebrate gap junctions are composed of connexins, a family of structurally related transmembrane proteins with molecular weights between 26,000 and 60,000.

ii. Each vertebrate hexagonal particle consists of six noncovalently associated connexin molecules. Each individual connexin molecule has two membrane-spanning α helices with a topology similar to that of claudin.

iii. The permeability of gap junctions is regulated by posttranslational modification of connexins (e.g., phosphorylation) and is sensitive to changes in environmental conditions

such as intracellular pH and Ca2+ concentration, membrane potential, and the intercellular potential between adjacent interconnected cells (“voltage gating”).

iv. The assembly of connexins, their trafficking within cells, and the formation of functional gap junctions apparently depend on N-cadherin and its associated adapter proteins as well as desmosomal proteins.

Which of the following statements are correct?

#Question id: 15746

#Unit 5. Developmental Biology

#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:

#Question id: 7284

#Unit 5. Developmental Biology

Choose the correct match.

#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: 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?