Which macromolecule forms a double layer as the primary structure of cell membranes? fats oils phospholipids steroids

The chemical form of energy that is useable by the cell to do work

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

How are fungi more like an animal? they have a cell wall. they are heterotrophs that absorb their food. they produce seeds and have membrane-bound nucleus. they use sunlight for photosynthesis.