Ageneral rule relating the capacity of a specific animal's digestive system to provide adequate access to substrates for biosynthesis of cellular components, as well as fuel molecules needed for atp production, is that the animal should have access to which ?

a diet that matches the "food pyramid" for the species.

Explanation:

The Food Pyramid makes healthy eating (i.e getting the correct amount of nutrients – protein, fat, carbohydrates, vitamins and minerals the body need to maintain good health) easier.

The Food Pyramid can also be a guide to help get the right balance of nutritious foods within the animal calorie limit.

answer; i believe that the correct answer is (lung);

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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