Receptor specificity Physical energy such as light, sound,
and heat is detected by specialized receptor cells in the sense
organs—eyes, ears, skin, nose, and tongue. When the action potential that
relays information about the stimulus through the nervous system to the brain. Sensory
receptors take in information from the environment, creating local electrical
currents; These currents are graded.
O1:2:1 because they are carbon, hydrogen and oxygen
Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
