Sixty six is D and sixty seven is A
Answer:
The sodium channel have refractory period.
Explanation:
Action potential are generated at axon hillock of neuron and travel across the neuron in response to stimuli. For the the generation of action potential the steps are stimulus, depolarization, repolarization, hyperpolarization and resting state.
So the first step for action potential after stimulus is depolarization. Depolarization requires the opening of sodium channels to make the inside of neuronal membrane positive. These sodium channels have refractory period. They cannot open immediately after activation. So the sodium channels of one direction in neuron (upstream) become refractory and it is convenent to open the sodium channels of other direction (downstream) of neuron. That why action potential is transmitted in one direction.
It is like the gunpowder placed at a line the fire cannot go back in burnt gun powder direction.
A population is a group of individuals of the same species that has the potential to interbreed.
- A population is described as a collection of people who belong to the same species and cohabit a particular area.
- A population is a subgroup of individuals belonging to a single species that coexists sexually and occupies a specific geographic area.
- For certain species, it is simple to determine the geographic limits of a population; for other species, it might be more challenging.
- For instance, the geographic range of plants or animals living on islands is determined by the island's border.
- On the other hand, other species are spread over very large areas, making it more challenging to define the borders of small populations.
learn more about population here: brainly.com/question/1437549
#SPJ4
You would need to have exothermic
Exothermic is when heat is being released
Hope this helps
