Life Processes in Animals

Overview

Animals carry out life processes to stay alive, including nutrition, respiration, transport and excretion. This chapter focuses on how animals get and use food and energy.

Key concepts

• Nutrition provides food and energy for the body.
• Digestion breaks food into simpler forms the body can use.
• Respiration releases energy from food using oxygen.
• The circulatory system carries nutrients and oxygen.
• Excretion removes waste from the body.

Important terms / formulae

• Digestion: breaking down of food into simple substances.
• Respiration: release of energy from food.
• Excretion: removal of waste products.
• Circulation: transport of materials through blood.

Solved example or key process

1. Food enters the mouth and is chewed.
2. It passes to the stomach and intestines for digestion.
3. Digested nutrients are absorbed into the blood.
4. Cells use oxygen to release energy from these nutrients.
5. Waste is removed through excretion.

Important questions

1. What is digestion?
2. Why do animals need to respire?
3. Name two waste products removed by the body.
4. What does the circulatory system do?

Quick revision

Animals stay alive through nutrition, digestion, respiration, circulation and excretion. Food is digested and absorbed, oxygen releases its energy, and wastes are removed from the body.