Answer:
D
Explanation:
Facilitated diffusion is a form of passive transport hence no energy is required by the cell. This means that while the molecules are moving down a concentration gradient – line normal diffusion – the movement of the molecules needs to be facilitated (in this case by a transmembrane protein) either because the molecule is polar and can't pass through the hydrophobic region of the cell membrane, or the molecule is too big to passively pass through the small natural pores of the cell membrane.
The three main ideas of cell theory are that:
<span>
1. All living things are made up of one or more cells. </span>
<span>2. Cells are the basic units of life in which activities of life occur. </span>
<span>3. Living cells come only from other existing and living cells. </span>
Answer:
Iron, Magnesium, and Nitrogen
Connected to the occipital bones
