Bacteria & Microbes Trivia

Bacteria were living on Earth long before anything with a backbone showed up, and they still outnumber us in almost every sense that matters. This quiz covers the shapes, discoveries, and everyday roles of the microbial world.

Meet the Prokaryotes

Bacteria are single-celled prokaryotes, meaning they lack a membrane-bound nucleus, and they come in three basic shapes: spherical cocci, rod-shaped bacilli, and spiral spirilla. They reproduce through binary fission, simply splitting in two, and clinicians still sort many of them using Gram staining, a technique that reveals differences in cell wall structure.

The Microbe Hunters

A handful of scientists built the entire field almost from scratch.

• Antonie van Leeuwenhoek — first person to observe bacteria under a microscope
• Louis Pasteur — advanced germ theory and developed pasteurization
• Robert Koch — linked specific microbes to specific diseases
• Alexander Fleming — discovered penicillin in a stray mold sample

Not All Bacteria Are the Enemy

Most bacteria aren't out to get you. Gut bacteria help with digestion, nitrogen-fixing bacteria in soil feed plants that would otherwise starve for usable nitrogen, and cultures like Lactobacillus turn plain milk into yogurt. The real trouble comes from a shrinking set of antibiotics working against bacteria that keep evolving resistance — and from the fact that none of it touches viruses, which aren't cells at all and simply don't have the targets antibiotics are built to hit.