Which substance on the plasma membrane identify chemical signals from outside the cell?
question 19 options:

carbohydrate chain

cholesterol

membrane protein

transport protein

Plzzz hurry im being timed ! humans, like other organisms, require energy for growth and repair. when cells create atp for energy, carbon dioxide is produced as a waste product. how does the body respond to this process in order to maintain homeostasis? a. the digestive and respiratory systems interact to move carbon dioxide to the lower intestine, where it is transformed into methane. b. the circulatory and digestive systems interact to move carbon dioxide to the stomach, where it to break down food. c. the nervous and urinary systems interact to move carbon dioxide to the kidneys, where it is absorbed into the bloodstream. d. the circulatory and respiratory systems interact to transport carbon dioxide to the lungs, where it is expelled from the body.

Environmental science are unconsidered with methods to preserve natural resourcesa.trueb.false

What is the difference between a scientific hypotheses and a scientific theory?