IMO Practice Test — Biological Classification
6 Questions • 15 min • Olympiad level
15:00
Question 1 of 6
Why was Linnaeus's two-kingdom system replaced by the Five Kingdom system?
It grouped very different organisms (e.g. bacteria, fungi, plants) together
It had too many kingdoms
It ignored animals
It was based on size only
Explanation: Two kingdoms could not separate prokaryotes, fungi and unicellular eukaryotes, so more kingdoms were needed.
Question 2 of 6
Diatomaceous earth is useful for filtration because the diatom walls are:
Made of fine, hard, indestructible silica
Soft and dissolve in water
Made of protein
Made of chitin
Explanation: The silica walls are hard and porous, ideal for filtration and polishing.
Question 3 of 6
Mycoplasma can survive in conditions that kill many other bacteria partly because it:
Lacks a cell wall and can live without oxygen
Has the thickest cell wall
Is photosynthetic
Is a eukaryote
Explanation: Without a cell wall and able to live anaerobically, mycoplasmas tolerate harsh conditions.
Question 4 of 6
Lichens are absent from heavily polluted cities, which makes them useful as:
Pollution indicators
Food crops
Antibiotics
Fertilisers
Explanation: Lichens do not grow where air is polluted, so their presence/absence indicates pollution.
Question 5 of 6
A virus crystallised and stored on a shelf shows no life signs, yet multiplies inside a host. This shows that viruses are:
On the borderline between living and non-living
Always non-living
Prokaryotes
Fungi
Explanation: Inert outside but reproducing inside a host, viruses sit at the boundary of living and non-living.
Question 6 of 6
Penicillin, an antibiotic, and the leavening of bread are both contributions of which kingdom?
Fungi
Monera
Protista
Animalia
Explanation: Penicillium gives penicillin and yeast leavens bread — both are fungi.