Starter: alive, dead or never alive?
Teacher
Write on the board: a seed, a car, a fire, a mushroom, a growing salt crystal, a sleeping cat, a wooden table. Students copy them into three columns in their exercise books: alive, dead (was once alive) and never alive. Give 2 minutes, then take answers by asking for a show of hands for each column.
The argument is the point: ask "A car moves and takes in fuel. A fire takes in fuel and gives out carbon dioxide. A crystal grows. Why aren't they alive?" Take two or three answers and draw out the key idea: a living organism shows all seven characteristics, while non-living things can show one or two.
Optional demonstration: if you have the yeast kit, set it up now (yeast, sugar and warm water in the bottle, balloon stretched over the neck) and leave it on the desk until the plenary. No kit? Skip it — you will draw and describe the result later.
Students
Sort the seven items into three columns in your exercise book. Be ready to say why you put the car and the fire where you did.
What to do
Sort these items into three columns — alive, dead (was once alive) and never alive: a seed, a car, a fire, a mushroom, a growing salt crystal, a sleeping cat, a wooden table. Then answer the two questions below and check your answers.
- 1.
Sort: a seed, a car, a fire, a mushroom, a growing salt crystal, a sleeping cat, a wooden table.
Alive: seed (alive but dormant — it respires slowly), mushroom (a fungus), sleeping cat. Dead (once alive): wooden table. Never alive: car, fire, salt crystal.
- 2.
A fire takes in fuel and oxygen and gives out carbon dioxide. Why is it not alive?
It shows only some features that look like characteristics. It does not reproduce to make more of the same kind of organism, is not made of cells and has no metabolism. A living organism shows all seven characteristics.
