"Water depth" is the factor among the choices given that has the <span>greatest importance in determining the characteristics of an aquatic ecosystem. The correct option among all the options given is the second option.
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Answer:
Any combination of D, E and F
Explanation:
Since A, B, and C belong to different orders, and D, E and F belong to the same order, the latter are more closely related and thus are expected to show a greater degree of structural homology. They are closer to their common ancestor than A, B and C.
Answer:
By action potential nerve contract the muscle
Explanation:
The muscle contract when the nervous system sends action potential to the muscle. So the nervous system delivers signal to muscle, the first signal reaches the neuromuscular junction. The signals are passed by a chemical messenger called neurotransmitter release by motor neurons, the chemicals bring reaction and shorten the muscle fibre. When neurotransmitter are absent or reduce in concentration the process reverse and muscle relax again.
Beneath the dermis, and is mainly used for fat storage
The nucleus contains the DNA and acts like a control center of the cell.
