How might the arctic fox population increase

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Amino acids contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. of the 20 amino acids found in humans, 11 are called "nonessential" because they can be manufactured by the body when needed. which elements in these 11 amino acids are commonly obtained from the metabolism of sugar molecules?

About how much of the cell mass is watet