1. natural selection acts on existing traits because you can not evolve into something you didn't have
2. original structures evolve to accomplish new function in order to survive
Answer:
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream.
Explanation:
Digestion works by moving food through the GI tract. Digestion begins in the mouth with chewing and ends in the small intestine. As food passes through the GI tract, it mixes with digestive juices, causing large molecules of food to break down into smaller molecules. The body then absorbs these smaller molecules through the walls of the small intestine into the bloodstream, which delivers them to the rest of the body. Waste products of digestion pass through the large intestine and out of the body as a solid matter called stool.
A) hypertonic because it has higher salt levels than inside
1.It is not natural.
2.It can came up with side effects and unbalance some species.
