Answer is A
Firstly axon must reach the threshold level and then depolarisation occurs. Depolarisation phrase means sodium enters and potassium leaves the axon . Choice C can't be because main idea is the entering of sodium ions.
Most likely D, because pesticides are poisonous to surrounding life.
Metabolic rate and production of by products of the ice fish increases with temperature
Oxygen is used by both autotrophs and heterotrophs to release energy from glucose (as we know, the bonds between organic compounds can be used to release energy) in a process known as cellular respiration. Carbon dioxide, however, is predominantly used in autotrophs to perform photosynthesis because they cannot get their food any other way. The type of organism that is both an oxygen producer and carbon dioxide consumer is an autotroph. This is because they release oxygen during photosynthesis and require carbon dioxide to perform photosynthesis.
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