Science Class 8
The Invisible Living World: Beyond Our Naked Eye
Tell bacteria, fungi, protozoa and viruses apart, and see what each does for us.
10 lessons · ~54 min total
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Lessons in this topic
- 0 Start here A living world too small to see, and what its members do for us. · 3 min You are here
- 1 A world below the eye An eye sees down to about 0.1 mm. A lens shows life far smaller than that. · 5 min
- 2 Four kinds, not one word Bacteria, fungi, protozoa and viruses are different kinds. Clues tell them apart. · 6 min
- 3 Microbes are everywhere Microbes live in water, soil, air, food and inside living things. · 6 min
- 4 The ones doing work we want Yeast, curd bacteria, compost microbes and root bacteria do jobs we want done. · 6 min
- 5 When food spoils Food spoils when microbes grow in it. Cold slows them but does not kill most of them. · 6 min
- 6 Helps or harms? Many microbes help us. Some harm us or our food. Judge by what the microbe does. · 6 min
- 7 Keeping microbes from growing A lot of salt or sugar stops most microbes growing. Drying and cold slow them. · 6 min
- 8 The big picture The whole chapter on one screen. · 3 min
- 9 Track quiz A cheat-sheet of the seven rules, then ten questions on microbes. · 7 min
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