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.
1. The central nervous system including brain and spinal cord.
2. The peripheral nervous system including nerves coming out from the brain and spinal cord, i.e., cranial nerves and spinal nerves.
3. The autonomic nervous system including sympathetic nervous system and parasympathetic nervous system.
Answer:
c) allowing an organism to adjust to changes in environmental conditions
Explanation:
A stimulus can be defined as any change in the external or internal environment that produces a corresponding response in the organism. These responses enable the organism to maintain an internal equilibrium (homeostasis). Gene expression in prokaryotes, which are the simplest forms of life, is highly regulated by environmental stimuli. Some examples of stimuli known to regulate gene expression patterns in prokaryotic organisms are light, water, pressure, temperature, etc.
Habitat, community, ecosystem,biome, biosphere
