Cells need a source of energy, they get this energy by breaking down food molecules to release, the stored chemical energy.
The correct answer is A.
Oswald Avery applied several biochemical techniques to large cultures of bacteria in order to extract and purify the "transforming principle". Their experiments showed that most probably the "transforming principle" was DNA. One of the observations leading to this conclusion was that enzymes that degrade proteins or RNA (such ribonucleases) had no effect on the "transforming principle". On the contrary, enzymes degrading the DNA destroyed the extract's transforming capacity.
Gastroesophageal Reflux Disease (GERD) ...
Gallstones. ...
Celiac Disease. ...
Crohn's Disease. ...
Ulcerative Colitis. ...
Irritable Bowel Syndrome. ...
A because they can eat out of the trash where the others require thenforest to live. Hope this helped.