Caveat Academy course · Grades 4 and 5

Microorganisms and the Invisible World: bacteria, yeast, molds and the microscope

Meet the living things too small to see: measure them in micrometers, look through Leeuwenhoek's single lens and a modern microscope at 400 times, watch one bacterium become 64 in two hours, blow up a balloon with yeast, find out how a moldy dish led to penicillin, learn why 20 seconds of scrubbing matters and how your body remembers a germ, and see how microbes make yogurt, clean water and filled the air with oxygen. Six modules at your own pace.

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$19one-time · every device you sign in on
Buy · $19

Included with the Caveat Academy pass and Whole-school licenses. Or get it in the Elementary explorers set, $49 for 6 items.

6 modules · 18 lessonsabout 13 hours$19

Six modules, eighteen lessons

Each module ends with a practice set that tracks mastery, an explain-it-back prompt, a short written response and a module exam. The final opens when every module is proficient; passing it earns a certificate with a verification code.

  1. Module 1: A world too small to see

    Sort microorganisms into bacteria, fungi, protists and algae, explain how viruses differ, and compare sizes in micrometers.

    • What microorganisms are
    • How small is small
    • Where microbes live
    about 2.1 h

  2. Module 2: Microscopes and the scientists who saw first

    Explain how Hooke, Leeuwenhoek, Pasteur and Koch discovered the microbial world, compute a microscope's total magnification and use one correctly.

    • Hooke, Leeuwenhoek and the first look
    • How a microscope works
    • Pasteur, Koch and germ theory
    about 2.1 h

  3. Module 3: Bacteria up close

    Describe the shapes and parts of bacteria, calculate growth by doubling and explain the ways bacteria help people and the planet.

    • Shapes and parts of bacteria
    • How bacteria multiply
    • Helpful bacteria
    about 2.1 h

  4. Module 4: Yeast, molds, protists and algae

    Explain fermentation by yeast, the discovery of penicillin and the roles of protists and algae, and design a fair test with one variable.

    • Yeast: the microbe in your bread
    • Molds and the discovery of penicillin
    • Protists and algae
    about 2.1 h

  5. Module 5: Germs and our bodies

    Explain how germs spread, why soap and 20 seconds of scrubbing work and how the body's layers of defense fight germs.

    • How germs spread
    • Washing away germs
    • How your body fights back
    about 2.1 h

  6. Module 6: Microbes at work

    Evaluate how microbes make food, recycle nutrients, clean water, make medicines and changed Earth's air.

    • Microbes in the kitchen
    • Microbes that recycle and clean
    • Microbes, medicine and the history of Earth
    about 2.1 h

Try it before you start

This is how every lesson works: step through a worked example at your own pace, then answer a check and get the reason right away. Nothing here is saved; the course keeps your progress.

Module 2 · How a microscope works

Worked example: total magnification

  1. The eyepiece magnifies 10 times.

A lesson check from each module

The checks need JavaScript turned on. The course itself works the same way.

What you get

Academics · Elementary$19 · included with the Academy pass and Whole-school licenses

What you finish with
A finished first course in microbiology: you can sort microbes into bacteria, fungi, protists and algae and explain how viruses differ, compare sizes in micrometers, tell the stories of Hooke, Leeuwenhoek, Pasteur, Koch and Fleming, compute a microscope's total magnification and use one correctly, describe bacterial shapes and calculate doubling growth, explain how bacteria, yeast, molds, protists and algae help people and the planet, design a fair yeast experiment, explain how germs spread and why soap and 20 seconds of scrubbing work, describe the body's layers of defense and evaluate how microbes make food, recycle nutrients, clean water, make medicines and changed Earth's air. Passing the final earns a Caveat certificate of completion.
Who it is for
Children in grades 4 and 5 who are curious about tiny living things, microscopes and how the body stays healthy, and homeschool families looking for a life science course with real experiments. A microscope helps but is not required. Experiments need yeast, sugar, balloons, plastic bottles, bread and zip-top bags; mold experiments stay sealed.
Format
An online self-paced course: 6 modules and 18 lessons with worked examples you reveal step by step, 144 practice and exam items (multiple choice, numeric, fill-in and ordering), an explain-it-back prompt and a rubric-checked short response in every module, module exams with one retake, a 24-question final and a certificate with a verification code. About 13 hours in all; works on a phone or a computer.
Access
$19 one-time, yours on every device you sign in on; the course opens once you are signed in with it. Included with the Caveat Academy pass and Whole-school licenses. Also in the Elementary explorers set ($49) and the Academics Suite pass ($149), and 1 more bundle. Progress is saved in this browser on this device, and the certificate page lets you download your record.
Where it lives
The Elementary space in Caveat Academics.
Support
Access, a receipt, a refund or a correction to the course: team@caveatacademic.com.

How it works

  1. Open the course and start Module 1. Each lesson takes about 25 to 35 minutes; two or three a week finishes the course in about a semester.
  2. Answer the checks as you read. Every answer shows the reason, and a miss links you back to the lesson that covers it.
  3. Finish each module with its practice set and exam. Proficient on every module opens the final; 70 percent passes it.
  4. Print or download your certificate and record from the certificate page.

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Sources and accuracy

The lessons are original writing by Caveat Academic Services. Facts were checked against these free, open references, which are also good places to read further.

  1. Centers for Disease Control and Prevention, handwashing: when and how to wash your hands: cdc.gov
  2. American Society for Microbiology, microbes, their history and their roles: asm.org
  3. Microbiology Society, microbes and the human body and the history of microbiology: microbiologysociety.org
  4. NOAA Ocean Service, how much oxygen comes from the ocean and phytoplankton: oceanservice.noaa.gov
  5. U.S. Department of Agriculture, leftovers and food safety, the two-hour rule: fsis.usda.gov
  6. Science History Institute, Alexander Fleming and the story of penicillin: sciencehistory.org

Microorganisms and the Invisible World is a self-paced enrichment course from Caveat Academic Services. It teaches microbiology for grades 4 and 5; it does not replace a school science course and awards no credit. The health lessons give general information about germs, hand-washing and the body's defenses and are not medical advice; questions about illness, medicines or vaccines belong with a doctor. Mold experiments stay sealed and are thrown away unopened, and hot water is handled by an adult. Support: team@caveatacademic.com.