The answer is graded potential<span>. Its made of various action potentials that depolarise the neuron incrementaly, in short interspersed intervals that do not give time for the neurons to return to resting potential. Therefore, the actions potentials, of varying sizes, grade up in sum and when they cumulatively reach the threshold level, they invoke an impulse in the nerve</span>
The answer to this question is:
Light (sunlight), water, and carbon dioxide! Oh, and chloroplasts.
When the Sun's energy moves through space, it reaches Earth's atmosphere and finally the surface. This radiant solar energy warms the atmosphere and becomes heat energy. This heat energy is transferred throughout the planet's systems in three ways: by radiation, conduction, and convection.
Answer:
They pick up oxygen from the lungs and drop off oxygen to the cells through the capillaries