Following statements are regarding to enzymatic processing of benzo(a)pyrene to a more potent mutagen and carcinogen.

A. Liver enzymes, particularly P-450 enzymes, modify benzo(a)pyrene in a series of reactions, producing 7,8-diol-9,10-epoxide, a highly potent mutagenic species that reacts with DNA primarily at the N2 atom of a guanine base.

B. The adduct, (+)-trans-anti-B(a)P-N2-dG, causes polymerase to insert an A rather than a C opposite the modified G base. Next time the DNA is replicated, a T will be inserted opposite the A, and the mutation will be complete.

C. Potent mutagen majorly causes conversion of guanine (G) to thymine (T) bases, a transition mutation.

D. When this potent mutagen applied to cultured bronchial epithelial cells, activated benzo(a)pyrene induces many mutations, including activating mutations at codons 175, 248, and 273 of the p53 gene.

Which of the following statements are correct?

TLS Online TPP Program

#Question id: 16953

#Unit 4. Cell Communication and Cell Signaling

The ability of any stem cell to self-renew and differentiate depends on the structural organization and cellular function of specialized anatomic microenvironments known as stem cell niches. These sequestered regions are typically populated by a supportive network of stromal cells. Stem cell niche stromal cells express soluble and membrane-bound proteins that regulate cell survival, proliferation, differentiation, and trafficking. Which statements is true about HSCs?

TLS Online TPP Program

#Question id: 16148

#Unit 4. Cell Communication and Cell Signaling

 Which statement is not true for NKT Cells?

TLS Online TPP Program

#Question id: 16147

#Unit 4. Cell Communication and Cell Signaling

 Which statement is not true for Natural killer (NK) cells?

TLS Online TPP Program

#Question id: 16146

#Unit 4. Cell Communication and Cell Signaling

If a given lymphocyte divides to form two daughter cells, both daughters bear antigen receptors with antigen specificities identical to each other and to the parental cell from which they arose, and so will any descendants they produce. The resulting population of lymphocytes, all arising from the same founding lymphocyte, is a clone. Which interleukin is responsible for clone production?

TLS Online TPP Program

#Question id: 16145

#Unit 4. Cell Communication and Cell Signaling

 Which line is not true for follicular dendritic cells?

TLS Online TPP Program

#Question id: 16144

#Unit 4. Cell Communication and Cell Signaling

  _______are motile phagocytic cells they play their most important role in the defense against multicellular parasitic organisms, including worms. They can be found clustering around invading worms, whose membranes are damaged by the activity of proteins released from its granules. it may also secrete cytokines that regulate B and T lymphocytes, thereby influencing the adaptive immune response.