1. What is food?write the different functions of food

Food is a source of energy that the body needs so that the body can function correctly and efficiently.

Depending on what types of food, food can give your body certain healthy nutrients such as certain vitamins, antioxidants, protein, calcium, fiber, etc. It can keep your body healthy, alive, allows you to move and work. It also helps in the process of building new cells and tissues for the body's growth process. It can help your body heal from wounds, cuts, bruises, etc. It can also help prevent and fight infections due to the nutrients in the foods.

Explanation:

answer; ///(b) it is composed of four protein chains and four heme groups;

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms