When cells communicate by the signaling process, one cell produces a signaling molecule that must be received by the signal receptor on or in the responding cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).
Answer:
C
Explanation:
Ice-covered surfaces are highly reflective of the sun's rays therefore prevent those areas from warming as much as the areas where the ice is replaced with darker, less reflective surfaces which absorb heat and thus contribute more to global warming. Albedo is the percentage of radiation reflected by the earth's surface. Clear surfaces have greater albedo values than dark surfaces.
Capillaries<span> are </span>small<span>, thin </span>blood vessels<span> that connect the </span>arteries<span> and the veins. Their thin walls allow oxygen, nutrients, carbon dioxide and waste products to pass to and from the tissue cells.</span>
Scientists make their hypothesis first, then they test it and collect the data
