Population growth is the change in the number of INDIVIDUALS in a population over time.
There was no sunlight, in one way or another sunlight is the source of almost all life on the surface of the earth
Transport proteins (carrier proteins and channel proteins) allow substances into and out of the cell that cannot pass through the phospholipid bilayer (as they’re either to large, charged or not lipid soluble) by facilitated diffusion.
Specifically channel proteins allow ions into and out of the cell by creating a pore in the membrane in which they can move through with their concentration gradient
"Lactose intolerance" means that your stomach has an extremely hard time digesting lactose, found in dairy products such as milk. For the second part of the question, can you tell me if you mean adapting to resist against lactose or the development of lactose from a long time ago.
The correct solution for this is explained the first option. Since water has an equivalent amount or number of H ions and OH ions, pure water itself is not slightly acidic nor basic. This equality of ions, causes the pH of water to be around the mid point of the pH scale which goes from 0 - 14, and thus is 7. This is a neutral pH.