Answer: CAPILLARIES
Explanation: Gas exchange is the delivery of oxygen from the lungs to the blood stream, and the elimination of carbon dioxide from the blood stream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessel is called capillaries, which are located in the walls of the alveoli.
The active site is <span> a site on the substrate molecule where specific enzyme molecules bind.</span>
An herbivore would belong to the second trophic level in an ecosystem. An herbivore is an animal that eats only plants, making it a consumer at the second level. The first trophic level is always made up of producers, or organisms that undergo photosynthesis such as plants.
Mechanical digestions is usually associated with the mouth. You mechanically chew the food and saliva breaks it down. Chemical digestion occurs in the stomach where stomach acid breaks it down.
