Answer:
small molecules easily pass through the phospholipids in the cell membrane
All living organisms are made of only 20 different aminoacids- this is the correct answer! This means that the genetic code only codes for those 20 aminoacids (for example Glutamine and Lysine).
The 20 aminoacids that can form proteins are also called Proteinogenic amino acids.
When the body becomes dehydrated, a chemical signal is sent that causes nephrons in the kidneys to absorb more water and excrete more salts. This is an example of a <em>D Feedback loop</em>.
