Nitrate reductase is an important enzyme for nitrate assimilation. Given below some regulation of nitrate reductase activity through phosphorylation and dephosphorylation.

a) Light, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby activates the enzyme

b) In Dark, and Mg2+ stimulate a protein kinase that phosphorylates the same serine residues, which then interact with a 14-3-3 inhibitor protein, and thereby inactivate nitrate reductase

c) In Light, and Mg2+ stimulate a protein kinase that phosphorylates the serine residues, and thereby activate nitrate reductase

d) In Dark, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby inactivates the enzyme

Which of the following statements about regulation of nitrate reductase is correct?

#Question id: 1535

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to cancer stem cell (CSCs).

a. A representative subpopulation of cancer cells with peculiar molecular aspects that resemble some of those typical of normal stem cells.

b. These cells are capable of replenishing the repertoire of identical cancer cells.

c. These cells cannot create heterogeneous progeny that differentiate into more mature cells.

d. These cells show extraordinary proliferative potential.

e. These cells show excessive programmed cell death.

Which of the following combination is correct?

#Question id: 1536

#Unit 4. Cell Communication and Cell Signaling

Use the following figure to answer the question. According to figure, which of the following statement is incorrect?

#Question id: 1537

#Unit 4. Cell Communication and Cell Signaling

Transformation of mature cells may also occur due to aberrant expression of stemness genes, resulting in cell clones with a dedifferentiated phenotype and self-renewing capacity resembling stem cells. Recent experimental evidence supporting this proposal has been provided with the induction of adult somatic cells into pluripotent stem (iPS) cells through ectopic expression of four genes encoding the pluripotency factors Oct4 and Sox2, the transcription factor Klf4, and the oncoprotein c-Myc in mouse or human fibroblasts. However, along with pluripotency comes the capability of generating teratomas. On the basis of the above information which of the following outcome is most appropriate?

#Question id: 1538

#Unit 4. Cell Communication and Cell Signaling

Many aspects of the biology of stem cells, including maintenance of pluripotency, self-renewal, and differentiation, are controlled by the phenomenon of RNA interference involving a variety of small molecules of RNA.

Match the following miRNA (Column I) with their target gene (Column II).

#Question id: 1539

#Unit 4. Cell Communication and Cell Signaling

Regulatory T cell (TREG) have identified by the presence of

#Question id: 1540

#Unit 4. Cell Communication and Cell Signaling

Peptidoglycans  recognize by