Lesson 2 ·Class 9 · Economic Importance of Bacteria and Fungi · Sort Lab
How Bacteria Feed
Four ways of getting a living.
Sort each bacterium or description by how it obtains food.
Sorted 0/8
All items sorted — check each bin.
Free play — sort every item into the bin it belongs in; each correct drop tells you why. Switch to when you're ready to test yourself.
Ask two questions: does it make its own food, and if not, is its source dead, harmed, or a partner?
What this lesson covers
Challenges to clear
- Fill the Symbiotic bin correctly.
- Sort every item.
- Fill the Autotrophic box — the bacteria that make their own food.
The task
Sort each bacterium or description by how it obtains food.
What this lesson covers
- Autotrophic — Makes its own food: Cyanobacteria, which photosynthesise using their own pigment (They make food from CO₂ and water, exactly as plants do.); Nitrifying bacteria, which use energy from chemical reactions (Chemosynthetic — they oxidise ammonia or nitrite for energy.)
- Saprophytic — From dead matter: Bacteria of decay, living on dead leaves and corpses (They secrete enzymes onto the dead matter and absorb the products.); Bacteria that turn milk sour (Lactobacillus feeding on the lactose in milk.)
- Parasitic — From a living host: Vibrio cholerae in the human intestine (It takes food from a living host and harms it.); Mycobacterium tuberculosis in the lungs (A pathogen — a parasite that causes disease.)
- Symbiotic — Mutual benefit: Rhizobium in the root nodules of a pea plant (It fixes nitrogen for the plant and receives food and shelter in return.); E. coli living in the human large intestine (It makes vitamin K and B-complex for us while we house and feed it.)
Hint
Ask two questions: does it make its own food, and if not, is its source dead, harmed, or a partner?