The best answer is A.
In a lysogenic cycle, the viral DNA or RNA enters the cell and integrates into the host DNA as a new set of genes called prophage. The prophage is passive and non virulent and does not destroy the cell. However if the prophage undergoes any stress or mutation or is exposed to UV radiation, it may adopt the lytic cycle and become infective.
In a lysogenic infection, there are no viral symptoms and it occurs after the viral infection is over. But the viral DNA or RNA remains in the cell and may remain there permanently .
It's responsible for motor control and balance and coordination of body and muscles.
Natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development and evolution
Explanation:
Percentage w/v means that weight of solute present in 100 ml of a solution. Hence, 15% w/v means that 15 gram of solute per 100 ml of solution.
Hence, for 2 L (or 2000 mL) preparation the amount of mass will be calculated as follows.

= 300 g
Thus, we can conclude that weight of Tris-HCL required is 300 g.