This chapter explains the life processes that help animals survive and function properly. It mainly focuses on nutrition and respiration in animals, especially humans. Animals obtain energy from food, which must be broken down into simpler substances through digestion. The chapter describes the structure and working of the human digestive system, including the role of organs like the mouth, stomach, small intestine, liver, and pancreas. It also explains how different animals digest food in different ways based on their eating habits. The chapter further discusses breathing and respiration, showing how oxygen is used to release energy from food and how animals have adapted different breathing organs to suit their habitats.
Key Points
Life processes are activities essential for survival, such as nutrition and respiration.
Nutrition provides energy needed for growth, repair, and daily activities.
Digestion breaks down complex food into simpler substances that the body can use.
The alimentary canal is a long tube from mouth to anus where digestion takes place.
Saliva begins digestion by breaking down starch into sugar.
The oesophagus pushes food to the stomach by wave-like movements.
The stomach churns food and uses acid and digestive juices to digest proteins.
The small intestine completes digestion and absorbs nutrients into the blood.
Liver secretes bile to help digest fats and neutralise acids.
Pancreas releases juices that digest carbohydrates, proteins, and fats.
The large intestine absorbs water and forms waste called stool.
Ruminants like cows chew food twice through a process called rumination.
Breathing involves inhalation and exhalation of air.
Respiration is the process of releasing energy from food using oxygen.
Alveoli in lungs help in exchange of oxygen and carbon dioxide.
Different animals breathe using lungs, gills, skin, or a combination of these.
Breathing is a physical process, while respiration is a chemical process.
👉 👉Life processes work together to keep animals alive and healthy. By understanding how our body functions and respecting healthy habits, we can protect our health and appreciate the diversity of life around us.