Topic: Absorption
Lesson 1: Nutrient and Water Absorption
| Section | Details |
|---|---|
| Objective | – Understand that nutrients are absorbed in the small intestine. – Recognize that water is absorbed primarily in the small intestine and partially in the colon. |
| Activities | Starter (5 mins): Show a diagram of the digestive system and ask students to identify where absorption might occur. Main (25 mins): 1. Explain the small intestine as the primary site of nutrient absorption. 2. Highlight the role of the colon in absorbing remaining water. 3. Discuss the importance of water and nutrient absorption in maintaining bodily functions. Plenary (10 mins): Students complete a labeling activity to identify the small intestine and colon on a digestive system diagram and summarize their roles in absorption. |
| Resources | Diagrams of the digestive system, labeling worksheets. |
| Time | 40 minutes |
| Homework | Write a paragraph explaining why nutrient and water absorption are essential for survival. |
| Assessment | Students correctly label the small intestine and colon and describe their roles in absorption during discussions and activities. |
| Past Paper Practice | IGCSE Biology 0610/21/M/J/20 Q5(a). |
Lesson 2: Structure and Function of Villi
| Section | Details |
|---|---|
| Objective | – Understand the significance of villi and microvilli in increasing the internal surface area of the small intestine. – Describe the structure of a villus and its role in absorption. |
| Activities | Starter (5 mins): Show a close-up diagram or animation of villi and microvilli and ask why they might be important for absorption. Main (25 mins): 1. Explain that villi and microvilli increase the surface area for absorption, ensuring efficient nutrient uptake. 2. Describe the structure of a villus: – Finger-like projections lined with epithelial cells. – Microvilli: Tiny projections on epithelial cells to further increase surface area. – Contain capillaries and lacteals for transport of absorbed nutrients. 3. Discuss the significance of each structure in nutrient absorption: – Capillaries: Absorb glucose, amino acids, and other water-soluble nutrients into the bloodstream. – Lacteals: Absorb fatty acids and glycerol into the lymphatic system. Plenary (10 mins): Students draw and label a villus diagram, including capillaries, lacteals, and microvilli. |
| Resources | Diagrams of villi and microvilli, animations, worksheets for drawing and labeling villi. |
| Time | 40 minutes |
| Homework | Write a brief explanation of how villi and microvilli help the small intestine absorb nutrients efficiently. |
| Assessment | Students accurately draw and label the structure of a villus and describe its role in absorption. |
| Past Paper Practice | IGCSE Biology 0610/22/M/J/19 Q4(b). |
Lesson 3: Roles of Capillaries and Lacteals in Villi
| Section | Details |
|---|---|
| Objective | – Describe the specific roles of capillaries and lacteals in the absorption process. – Relate their structure to their functions in transporting nutrients. |
| Activities | Starter (5 mins): Show a diagram of the villus and ask students to predict the roles of the capillaries and lacteals. Main (25 mins): 1. Discuss the role of capillaries in absorbing water-soluble nutrients: – Transport glucose, amino acids, vitamins, and minerals into the bloodstream. 2. Explain the role of lacteals in absorbing fat-soluble nutrients: – Transport fatty acids and glycerol into the lymphatic system. 3. Highlight the close proximity of capillaries and lacteals to the epithelial layer for efficient absorption. Plenary (10 mins): Students write a short summary comparing the functions of capillaries and lacteals in nutrient absorption. |
| Resources | Diagrams of villi with labeled capillaries and lacteals, comparison worksheets. |
| Time | 40 minutes |
| Homework | Create a table comparing the roles of capillaries and lacteals in nutrient transport. |
| Assessment | Students summarize and compare the roles of capillaries and lacteals during discussions and written activities. |
| Past Paper Practice | IGCSE Biology 0610/31/O/N/20 Q3(a). |
Key Notes for Teachers:
- Use diagrams and animations to help students visualize the structures of villi and microvilli.
- Emphasize the relationship between structure and function in absorption.
- Provide hands-on activities like labeling and diagram creation to reinforce learning.
Key Notes for Students:
- The small intestine is the main site of nutrient absorption, with water absorption occurring in the small intestine and colon.
- Villi and microvilli increase the surface area of the small intestine, ensuring efficient absorption.
- Capillaries absorb water-soluble nutrients, while lacteals absorb fat-soluble nutrients.
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