A secondary source is anything written after the fact
Porosity
Porosity refers to the space inside the rock that is taken up by pore space.
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>
So we know that to transport materials in or out of the cell, we need to have access to both the inside and outside of the cell. This would require that the protein be a transmembrane protein that reaches both the inside and the outside of the cell.
So in this case, let's look at pore proteins. These are proteins that cross a membrane and act as a pore for the materials that need to cross the membrane.
One example of a pore protein is an aquaporin. These proteins aid in the transport of water into or out of a cell.
Therefore, the answer to your question is: A) Pore proteins.
