A) Define digestion and egestion. b) Draw the human alimentary canal. c) State three reasons for cooking and preserving food.

a) Define

• i) Digestion: The process by which complex, insoluble food substances are broken down into simpler, soluble, and absorbable forms by mechanical and chemical means.
• ii) Egestion: The process of eliminating undigested and unabsorbed food material (feces) from the body through the anus.

b) Draw a large well labeled diagram of the human alimentary canal.

I cannot draw diagrams. However, a well-labeled diagram of the human alimentary canal should include the following organs:

• Mouth
• Pharynx
• Esophagus
• Stomach
• Small Intestine (Duodenum, Jejunum, Ileum)
• Large Intestine (Cecum, Colon, Rectum)
• Anus It should also show associated glands like the salivary glands, liver, gallbladder, and pancreas.

c) State three (3) reasons in each case why it is important for food to be

• i) Cooked

  1. Cooking kills harmful microorganisms such as bacteria, viruses, and parasites, making the food safe for consumption.
  2. It improves the digestibility of food by breaking down tough fibers and complex molecules, allowing for easier nutrient absorption.
  3. Cooking enhances the flavor, aroma, and texture of food, making it more palatable and enjoyable to eat.

• ii) Preserved

  1. Preservation prevents food spoilage by inhibiting the growth of microorganisms like bacteria and fungi, and slowing down enzymatic reactions.
  2. It extends the shelf life of food, reducing waste and allowing it to be stored for longer periods.
  3. Preservation ensures food availability throughout the year, especially for seasonal produce, and facilitates its distribution to different regions.