In light reaction, the funneling of excitation from the antenna system toward the reaction centre has been shown,

a.) The excited-state energy of pigments increases with distance from the reaction centre; that is, pigments closer to the reaction centre are lower in energy than those farther from the reaction centre

b.) The energy gradient ensures that excitation transfer toward the reaction centre is energetically favorable and that excitation transfer back out to the peripheral portions of the antenna is energetically unfavourable

c.) Some energy is lost as heat to the environment by this process, but under optimal conditions almost all the excitation energy absorbed in the antenna complexes can be delivered to the reaction centre

d.) The excited-state energy of  pigments decreases with distance from the reaction centre

Which of the following above combination is true?

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.