Quiz on Bacteria

Which everyday dairy product is made by bacteria fermenting milk?

• Butter
• Yogurt ✓ (Correct answer)
• Ice cream
• Cream

Source: Live bacteria sour the milk and thicken it — that tangy taste is bacteria working for you, not against you.

Antibiotics are medicines designed to kill which kind of germ?

• Viruses
• Fungi
• Bacteria ✓ (Correct answer)
• Allergens

Source: This is why antibiotics do nothing for a cold or flu — those are viruses, and antibiotics only hit bacteria.

Roughly how large is a typical bacterium?

• A few micrometres ✓ (Correct answer)
• A few millimetres
• A few centimetres
• A few metres

Source: Thousands of them could line up across a single grain of salt — far too small to see without a microscope.

Helpful live bacteria sold in supplements to support gut health are called what?

• Prebiotics
• Probiotics ✓ (Correct answer)
• Antibiotics
• Antioxidants

Source: Probiotics add good bacteria; prebiotics are just the fibre that feeds them — one delivers the bugs, the other the lunch.

Unlike plant and animal cells, bacteria have no true what?

• Nucleus ✓ (Correct answer)
• Cell membrane
• Cytoplasm
• DNA

Source: Bacteria keep their DNA loose in the cell with no nucleus to wrap it — that's what makes them prokaryotes.

Alexander Fleming famously discovered which bacteria-killing medicine?

• Aspirin
• Insulin
• Vaccine
• Penicillin ✓ (Correct answer)

Source: He spotted mould killing bacteria on a forgotten dish — penicillin was born from a happy lab accident.

How do most bacteria reproduce?

• Laying eggs
• Budding off
• Producing seeds
• Splitting in two ✓ (Correct answer)

Source: One cell just copies itself and divides — given food, a single bacterium can become billions overnight.

Which vaccine-preventable disease comes from bacteria entering deep wounds?

• Tetanus ✓ (Correct answer)
• Rabies
• Malaria
• Flu

Source: The 'rusty nail' fear is real — tetanus bacteria thrive in deep, airless wounds, which is why a booster matters.

Eating undercooked chicken or raw eggs risks infection by which bacteria?

• Listeria
• E. coli
• Staphylococcus
• Salmonella ✓ (Correct answer)

Source: Salmonella is the classic poultry-and-eggs culprit — which is why cooks are warned to cook chicken right through.

Friendly bacteria in the human gut help produce which vitamin?

• Vitamin C
• Vitamin D
• Vitamin K ✓ (Correct answer)
• Vitamin A

Source: Your gut bugs quietly manufacture vitamin K, which your body needs to clot blood and heal cuts.

Tuberculosis, a serious bacterial disease, mainly attacks which organ?

• Liver
• Kidneys
• Lungs ✓ (Correct answer)
• Heart

Source: TB targets the lungs and spreads through the air — once it was the leading cause of death across Europe.

Botox, the wrinkle treatment, uses a toxin from bacteria that cause which illness?

• Botulism ✓ (Correct answer)
• Cholera
• Anthrax
• Dysentery

Source: One of the deadliest toxins known, in tiny doses, smooths wrinkles — botulism bacteria are behind both.

The Gram stain test sorts bacteria into two groups based on their what?

• DNA length
• Cell wall ✓ (Correct answer)
• Body shape
• Cell size

Source: A thick wall traps the purple dye and holds it; a thin one lets it wash out — that single difference guides which drug to use.

What is the proper name for rod-shaped bacteria?

• Cocci
• Spirilla
• Bacilli ✓ (Correct answer)
• Vibrio

Source: Bacilli are the rods, cocci the spheres — bacteria are often named straight from their shape under the microscope.

The medieval plague known as the Black Death was mostly spread by what?

• Mosquitoes
• Fleas ✓ (Correct answer)
• Contaminated water
• Coughing

Source: Fleas riding on rats carried the plague bacteria from town to town — the rats took the blame, the fleas did the work.

Bacteria in the roots of bean plants pull which gas from the air?

• Oxygen
• Carbon dioxide
• Hydrogen
• Nitrogen ✓ (Correct answer)

Source: These root bacteria turn unusable air nitrogen into plant food — a natural fertiliser factory underground.

Some deep-sea bacteria create their own glow through which process?

• Photosynthesis
• Fluorescence
• Phosphorescence
• Bioluminescence ✓ (Correct answer)

Source: Many anglerfish 'lanterns' aren't the fish at all — they're glowing bacteria living inside, making light on demand.

Whose swan-neck flask experiment disproved that life arises from nothing?

• Louis Pasteur ✓ (Correct answer)
• Robert Koch
• Joseph Lister
• Edward Jenner

Source: Pasteur proved broth stays clear unless bacteria drift in — killing the old 'spontaneous generation' idea for good.

The sticky plaque that bacteria form on your teeth is an example of a what?

• Spore
• Colony
• Biofilm ✓ (Correct answer)
• Culture

Source: A biofilm is a bacterial city in slime — and the same survival trick coats medical implants and old water pipes.

Bacteria swap antibiotic-resistance genes using small rings of DNA called what?

• Chromosomes
• Plasmids ✓ (Correct answer)
• Ribosomes
• Mitochondria

Source: These little DNA rings pass between bacteria like trading cards — which is how resistance spreads so alarmingly fast.