They provide the immune system with "memory" against previously encountered pathogens.
T memory cells are necessary for protective immunity against invading pathogens
The question has incorrect option, however the question can be answered by the general explanation. On the basis of the general explanation the answer is as follows:
Answer:
The correct answer is - Serine has a small side chain that can fit in any relatively polar environment.
Explanation:
Serine is an amino acid that have a small side chain in comparison of other amino acid and can be replaced by another amino acid with very least effect on the structure and function of a particular protein as they can fit in any relatively polar environment.
Serine have hydroxyl group in their side chain. It is polar amino acid that can easily establish itself in any polar condition and cause least changes in protein structure and function.
Thus, the correct answer is - Serine has a small side chain that can fit in any relatively polar environment.
Answer:
C
Explanation:
The Calvin cycle occurs in three major phases:
1) Carbon fixation; which involves the reaction of CO2 with a phosphorylated Co2 acceptor called Ribulosebiphosphate(RuBp) as catalysed by Rubisco enzyme. Due to the instability of the formed six-carbon compound, it breaks into two molecules of 3-phosphoglycerate (PGA)
2) Reduction; The PGA is phosphorylated by ATP to form 1,3-biphosphoglycerate, which is then reduced by NADPH to form glyceraldehyde-3-phosphate (G3P).
3) Regeneration; The final step, which is very important for the continuity of Calvin cycle is the regeneration of the CO2 acceptor (RUBP). The molecules of G3P are rearranged into molecules of Ribulosephosphate(RuP) by series of complex reactions, which is then phosphorylated by ATP to form RUBP, ready to accept CO2 for the cycle to continue