The answer is:
A) Cells are the basic unit of life.
The ileum contains villi that project into the lumen and increase the amount of surface area.
Villi are small finger-like structures that project into the lumen of the small intestine. Villi increase the surface area of the intestinal walls for easy and quick absorption of digested food with the addition of digestive secretions. Villi vary in length from about 0.5 to 1 mm. They are usually found in large numbers at the beginning of the small intestine and they reduce toward the end of the tract.
Answer:
El sistema nervioso tiene dos partes principales: El sistema nervioso central está compuesto por el cerebro y la médula espinal. El sistema nervioso periférico está compuesto por todos los nervios que se ramifican desde la médula espinal y se extienden a todas las partes del cuerpo.