Cellular senescence may have evolved to protect organisms against cancer. Instead of dividing out of control, the cells die. Cellular senescence appears to be regulated by several tumor suppressor genes, especially p53.what is the most appropriate reason behind this,

1) Transcription factor p53 is thought to suppress tumorigenesis by causing cell arrest and senescence in response to short telomeres, DNA damage, and viral or external signals to divide

2) This factor can stop the cell cycle, cause cellular senescence in rapidly dividing cells, instruct genes to initiate cellular apoptosis, and activate DNA repair enzymes.

3) Induction of apoptosis or cellular senescence by p53 always beneficial.

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#Question id: 13059

#Unit 13. Methods in Biology

Precision will be reduced, but yield will be increased

Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

Efficiency during ligation of blunt ended insert and vector cannot be cannot be enhanced by means of…..

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#Question id: 12525

#Unit 6. System Physiology – Plant

The role of ABA signaling during water stress in the guard cells in presence and absence of ABA;

a) Anion effl¬ux leads to depolarization of the plasma membrane, which drives K+ effl¬ux. The eff¬lux of ions (A– and K+) reduces the turgor pressure of guard cells, resulting in stomatal closure.

b) Both OST1 and CPKs phosphorylate and thereby activate plasma membrane anion channels, leading to ef¬flux of anions (A–). But  this process can be inhibited directly by PP2Cs 

c) Inhibition of PP2C activity releases the positive regulator kinase OST1 from inhibition, resulting in both phosphorylation and activation of NADPH oxidases (RBOHs)

d) RBOHs catalyze the formation of apoplastic reactive oxygen species (ROS),  which triggers opening of plasma membrane Ca2+-permeable ion channels 

e) The resulting elevation of cytosolic Ca2+ leads to activation of calcium-dependent protein kinases (CPKs), which can also activates the RBOH proteins further promoting Ca2+ infl¬ux into the cytosol.

Which statements belongs to the presence and absence of ABA during signalling;

I. In presence of  ABA

II. In absence of ABA

Which of the following combination from the given above statements is correct?

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#Question id: 1748

#Unit 4. Cell Communication and Cell Signaling

Which of the folllowing is a cytokine receptor that is a member of the hematopoietin receptor family?

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#Question id: 13060

#Unit 13. Methods in Biology

Precision will be reduced, but yield will be increased

Optimisation of a PCR reaction is often a compromise between the competing demands for precision, efficiency and yield. Although the specific effects may vary, generally, increasing the annealing temperature will increase non-specific primer binding and reduce precision. Increasing the length of the elongation phase will reduce the proportion of incomplete newly-synthesised strands and therefore increase yield. In this case, the potential effect on efficiency is unclear. Increasing the elongation phase would increase the reaction time, but the time taken to ramp down to a lower annealing temperature would be reduced.

In blue white screening insertional activation of Beta-D-galactosidase will give rise to

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#Question id: 26459

#Unit 3. Fundamental Processes

Which region of sigma acts as a molecular mimic of DNA