Answer:
a) Acetylcholine is degraded by acetylcholinesterase.
Explanation:
After it binds for its receptor on the plasma membrane of the postsynaptic cell, acetylcholine must be removed in order to prevent repeated stimulation. Acetylcholinesterase is enzyme for the inactivation of acetylcholine, present at all cholinergic synapses. This enzyme hydrolyses acetylcholine and breaks it to the acetate and choline. Choline can be reused for the synthesis of the new acetylcholine molecule so it is taken back into the presynaptic cell.
Answer:
False
Explanation:
it can be used to date stuff up to about 50000 years, so i'd say that its halfly false, so false is correct :)
Answer:
Option B, 
Explanation:
Given-
The average surface area of one foot pad of an elephant is

Weight of an Asian elephant is
newton
As we know, pressure is equal to total weight divided by total area of the surface on which it is concentrated.
Thus, pressure on one foot pad of elephant is 

Hence, option B is correct answer
Answer:
1- Presence of phenotypic variation
2- some phenotypic variation due to genetic variation
3- the given trait has an impact on fitness
Explanation:
The evolutionary theory by natural selection proposed by Darwin in his publication “On the origin of species” (1859) is based on a series of assumptions that enable to understand the amazing biodiversity on the Earth. First, individuals are not identical among them, i.e., there exists variation in the traits among the members of a given population, species, etc. Second, phenotypic variation leads to differential survival and reproduction of the organisms that are best fitted to the environment (i.e., competence among the members of the population). Finally, phenotypic traits are passed from generation to generation (i.e., phenotypic variation is inheritable), thereby favoring offspring from parents more adapted to the environment.