Question

1. why do animals need to breathe?

Explanation:

Animals need to breathe to obtain oxygen for cellular respiration. Cellular respiration is the process by which cells convert nutrients (such as glucose) into energy (ATP). Oxygen is required in this process as the final electron acceptor in the electron transport chain. Without oxygen, animals would not be able to produce enough energy to carry out essential life functions like movement, growth, and maintaining homeostasis. Additionally, breathing also helps in getting rid of carbon dioxide, a waste product of cellular respiration. If carbon dioxide accumulates in the body, it can disrupt the body's pH balance and cause harm to cells.

Answer:

Animals need to breathe to obtain oxygen for cellular respiration (to produce energy) and to expel carbon dioxide (a waste product).