Answer:
A <u><em>receptor</em></u> is a protein that recognizes and responds to a signal.
Explanation:
A receptor is a protein molecule present on the cells on which the signalling molecules can bind and generate a physiological response. Some receptor molecules can also respond to Sun and light. Each type of cell has specific receptors molecules and hence can respond to specific signals. The receptor molecules hence tend to receive signals for a cell. Molecules such as hormones bind to the receptors.
Atherosclerosis refers to the build-up of fats and cholesterol in the walls of blood vessels (Option A).
<h3>What is atherosclerosis?</h3>
Atherosclerosis is a disease characterized by the build-up of fats and cholesterol in the walls of blood vessels.
This build-up of fats narrows the blood vessels, thereby difficulting the movement of blood in the bloodstream.
The symptoms of atherosclerosis include, among others, chest pain, shortness of breath and fatigue.
Learn more about atherosclerosis here:
brainly.com/question/4142223
There are radio waves, microwaves and infrared waves
The answer is either a or c