What you need
• A plastic knife
• A ripe banana
• 2 plastic bags
• 2 rubber bands
• Teaspoon
• Dry yeast
• Permanent marker

Steps
1. Peel the banana
2. Cut two equal slices from the banana.
3. Place one slice of the banana into each plastic bag.
4. Sprinkle half a teaspoon of yeast onto one of the banana slices in one of the bags
5. Seal both bags tightly with rubber bands
6. Label the bag containing yeast ‘Y’.
7. Leave the bags in a warm place.
8. Observe the bags daily for one week.

Describe what you see and explain why it happens that way.