BASIC SCIENCE E-NOTE
Class:
Grade 8 (JSS 2)
Topic:
Digestive System
Problems
Associated with the Digestive System
Some common problems of the
digestive system include:
1.
Indigestion
This occurs when food is not
properly digested.
Causes: overeating, eating too fast, oily food.
2.
Diarrhoea
This is frequent passing of watery
stool.
Causes: dirty food, unclean water, germs.
3.
Constipation
This is difficulty in passing stool.
Causes: lack of fibre, drinking little water.
4.
Food Poisoning
This happens when a person eats
contaminated food.
Symptoms: vomiting, stomach pain, diarrhoea.
Prevention
of Digestive System Problems
- Wash hands before eating
- Eat clean and well-cooked food
- Drink clean water
- Eat balanced diet
- Avoid overeating
Simple
Food Tests
Food tests help us to know the type
of nutrient present in food.
1.
Test for Glucose
Reagent: Benedict’s solution
Procedure: Add Benedict’s solution to food and heat.
Observation: Brick-red colour shows glucose is present.
2.
Test for Starch
Reagent: Iodine solution
Procedure: Add iodine to food sample.
Observation: Blue-black colour shows starch is present.
3.
Test for Protein
Reagent: Biuret solution
Procedure: Add Biuret solution to food sample.
Observation: Purple or violet colour shows protein is present.
4.
Test for Fats and Oil
Reagent: Ethanol
Procedure: Add ethanol and shake, then add water.
Observation: Milky white colour shows fats and oil are present.
Importance
of Food Tests
- Helps us know the nutrients in food
- Helps in choosing balanced meals
- Helps maintain good digestive health
Class
Activity
Students carry out simple food tests
in groups and record their observations.
Quick
Revision
- Digestion breaks food into simple substances
- Poor hygiene can cause digestive problems
- Food tests help identify nutrients in food
Assignment
- List three digestive system problems and their causes.
- Draw a table showing food tests and their observations.
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