What are microorganisms?

Living things too small to see without a microscope

Are most bacteria harmful to humans?

No, most are harmless or helpful

Why are viruses often not considered living?

They can only reproduce inside host cells

What is the human microbiome?

The microbes living in and on our bodies

Microorganisms Quiz: Can You Get 8 Out of 10?

This microorganisms quiz covers bacteria, viruses, fungi, protists, yeast, helpful and harmful microbes and the human microbiome. Can you get 8 out of 10 on the tiny life forms that shape health, food and the planet?

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🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Size
What are microorganisms?
Bacteria
Are most bacteria harmful to humans?
Viruses
Why are viruses often not considered living?
Yeast
Yeast is what kind of organism?
Penicillin
Penicillin comes from which kind of microorganism?
Protists
Which is a protist that causes malaria?
Microbiome
What is the human microbiome?
Oxygen
Which tiny organisms produce much of Earth's oxygen?
Food
Which food is made with bacteria?
Extreme
Microbes that live in boiling hot springs are called what?

Explanations: answer key for all 10 questions

Q1: What are microorganisms?
Answer: Living things too small to see without a microscope
Most are single-celled.
Q2: Are most bacteria harmful to humans?
Answer: No, most are harmless or helpful
Gut bacteria help digest food.
Q3: Why are viruses often not considered living?
Answer: They can only reproduce inside host cells
They lack their own cell machinery.
Q4: Yeast is what kind of organism?
Answer: A fungus
It makes bread rise and ferments beer.
Q5: Penicillin comes from which kind of microorganism?
Answer: A mold
Fleming discovered it in 1928.
Q6: Which is a protist that causes malaria?
Answer: Plasmodium
It is spread by mosquitoes.
Q7: What is the human microbiome?
Answer: The microbes living in and on our bodies
It may contain trillions of microbes.
Q8: Which tiny organisms produce much of Earth's oxygen?
Answer: Ocean phytoplankton
They photosynthesize like plants.
Q9: Which food is made with bacteria?
Answer: Yogurt
Bacteria ferment milk sugars.
Q10: Microbes that live in boiling hot springs are called what?
Answer: Thermophiles
Some thrive above 100 °C under pressure.

Microorganisms Quiz – Tiny Life, Big Impact

Microorganisms are living things too small to see with the naked eye. They include bacteria, archaea, fungi such as yeast and molds, protists and microscopic algae. Viruses are often grouped with them, although they need host cells to reproduce.

Microbes are everywhere: in soil, oceans, air and inside our bodies. Most are harmless or helpful. They recycle nutrients, produce oxygen, make food like bread and cheese and help digest our meals. Some cause diseases, such as tuberculosis, malaria and the flu.

Studying microbes has transformed medicine and industry. Antibiotics, vaccines and fermented foods all depend on them, and research on the microbiome shows how gut bacteria influence health. Microbes may even hold clues to life on other planets.

What This Quiz Teaches

This quiz is for students exploring microorganisms.

What microorganisms are
Whether bacteria are harmful
Why viruses are different
What yeast is
What the microbiome does

Did You Know?

Leeuwenhoek first saw bacteria in the 1670s.
Tardigrades are tiny animals, not microbes.
Some bacteria glow in the dark.
Soil teems with billions of microbes per handful.
Archaea were recognized as a domain in 1977.