Asei

ASEI/PDSI LESSON PLAN

TOPIC: Nutrition and transport in plants
SUBTOPIC: Osmosis

LESSON TOPIC: Effect of salt concentration on the mass and length of Irish potatoes
DURATION: 40 min.
FORM:   3
PARTICIPANTS: 40
DATE: 06/01/10

RATIONALE:
Osmosis is a special type of diffusion. It is defined as the movement of water (solvent) molecules from an area of low concentration (low solute concentration) to an area of high solute concentration through the semi permeable membrane. The membrane is selectively permeable and only allows the water and very small molecules to pass through freely. Large solute molecules e.g. sucrose molecules cannot pass through it.
It is imperative therefore for the learners to have knowledge of this process which would be used in the understanding of how the digested food molecules in their bodies move from the gut into the body cells.

OBJECTIVES:
By the end of the lesson learners should be able to:
  a) Identify different variable in the given data
  b) Slice well measured pieces of Irish potato.
  c) Graphically present information of length against concentration.

TEACHING/LEARNING MATERIALS
4-different concentrations of salt /sugar (5%,10%, 15%, and 20%), beakers(tins), razor blades, Irish potatoes rulers and distilled water, threads,(strings), and (straight)30 cm dry sticks.
REFERENCES,
  Medi I. K. & Meredith H. M. (1989). The Senior Certificate Biology, Dzuka Publishing Co. Ltd, Blantyre, Malawi. Pages 97-99.





LESSSON PROCEDURE
|Lesson Sequence       |Teaching/Learning Activities                                             |Learning Points                             |
|Introduction           |Ask learners to:                                                         |                                           |
|(5 min)               |define osmosis                                                           |Recap of the prior knowledge and making     |
|                       |Explain the difference...