Answer:
The weight-average molar mass of polystyrene is 134,160 g/mol.
Explanation:
Molar mass of the monomer styrene , 
, M=104 g/mol
Given , number average molar mass of the polymer , M'= 89,440 g/mol
Degree of polymerization = n
The weight-average molar mass = 
Molar mass dispersity is ratio of weight-average molar mass to the number average molar mass of the polymer.
The weight-average molar mass of polystyrene is 134,160 g/mol.
Answer : Option B) Plant stomata opening and closing to maintain homeostasis.
Explanation : Claude Bernand was a French Physiologist who first discovered about "homeostasis" which is defined as the controlled stability of the internal milieu, or internal environment, of cells and tissues in plants.
In plants stomatal opening and closing was done for maintaining homeostasis with the external and internal plant environment.
Answer:
The population of the long-legged birds decreases.
Explanation:
The population of the short-legged birds increases whereas the population of long-legged birds decreases due to availability of food in that environment. The long-legged birds feed on fish whose population decreases due to drought conditions so the population of long-legged birds also decreases while on the other hand, the population of short-legged birds increases or remain the same because they feed on the insects and the insects are available in large amount and less affected by the drought conditions.
