CDC vs kitchen
Public pages talk about strep or Salmonella. They rarely mention the starter in a yogurt pot — both are bacteria.
Darker cells mean a higher score for this topic on that metric.
Familiarity95
Medical weight72
Benefit78
Risk55
Research90
Live debate30
LessMore
Each bar is a 0-100 atlas score for this topic, not a timeline.
Both scores stay visible. Drag the slider to emphasize Benefit or Risk.
Benefit
Risk
Familiarity
95%
Milestones in order. This is history, not a weekly activity grid.
- Animalcules seen
- Pasteur & spoilage
- Koch's anthrax
- Gram stain
- Penicillin noted
- Streptomycin
- Carl Woese's split
- First bacterial genome
Last reviewed Sources & creditsMedia creditsMethodology
Encounter route pick
Pick one encounter or route already written on this topic and reopen it next time.
Classroom literacy — not a lab result, diagnosis or outbreak alert.
Route on this page
One encounter scale
Scale literacy. Not a lab result or a diagnosis.
Quick facts
0.5–5 µmTypical size
Bacteria (not Archaea)Domains
Peptidoglycan / Gram stainCell wall cue
1676 — van LeeuwenhoekFirst seen
Millions, mostly unculturedEstimated species
Similar order of bacterial cells in/on usHuman cells vs microbes
Bacteria are prokaryotes: DNA is not wrapped in a nucleus, ribosomes make protein, and many species build a peptidoglycan wall that Gram stain still uses as a first map.
They invented photosynthesis, nitrogen fixation and fermentation long before animals existed. Most lineages never infect a human; a minority of specialists cause famous diseases.
This atlas treats bacteria as a tree of life, not a synonym for 'germ'. Beneficial, environmental and pathogenic stories sit in later topics.
95FamiliarityEditorial 0–100 browsing aid within this atlas.
72Medical weightEditorial 0–100 browsing aid within this atlas.
78BenefitEditorial 0–100 browsing aid within this atlas.
55RiskEditorial 0–100 browsing aid within this atlas.
Bacteria — concrete atlas depth on Tool-Lifes.
Bacteria — concrete atlas depth on Tool-Lifes.
Not a synonym for germ
English still uses germ for any unwelcome microbe. This atlas keeps bacteria as a domain of life that also makes food.
FDA food cultures
Listed cultures in dairy are ingredients, not infections. Labels still use Latin binomials.
Public-health desks
Germ, bug and bacteria collapse in casual English. Keep the domain word when you mean the tree of life.
The profile
- Familiarity95
- Medical weight72
- Benefit78
- Risk55
- Research90
- Live debate30
Risk
Single-celled prokaryotes with cell walls — the oldest widespread life form, and both partners and pathogens.
Seven ways into this topic
Related on the scale
Slide across the log scale — teaching sizes, not lab measurements.
Frequently asked questions
Where should I start with Bacteria?
Read Identity → How they live → Body & health, then use compare rails.
Is this page advice for Bacteria?
Public-health education — not a care plan, prescription, or outbreak briefing.
What does the local lens add?
It names everyday desks for Tree of microbes before English norms look universal.
Are the scores a ranking of Bacteria?
No — editorial 0–100 browsing aids inside this atlas only.
How do I compare Bacteria to neighbours?
Use related cards and best-of / quiz rails after the first three chapters.
Which chapter is densest?
How they live and Body & health carry mechanisms; skim Identity first.
Can I cite these scores externally?
Treat them as atlas orientation, not certificates or forecasts.
What should I check before acting?
Primary desks for Tree of microbes: public-health desks and lab teaching frames.
Sources & research
More in Tree of microbes
Viruses
Packets of DNA or RNA that are not cells — they replicate only inside living hosts.
Familiarity 96Fungi
A eukaryotic kingdom of yeasts, moulds and mushrooms — chitin walls, external digestion, partners of plants.
Familiarity 80Archaea
A prokaryotic domain that is not bacteria — methanogens, extremophiles and no known human pathogens.
Familiarity 35Bacteriophages
Viruses that infect bacteria — Earth's most abundant biological entities, and a concept-level idea in medicine.
Familiarity 42Protozoa
Motile unicellular eukaryotes — a teaching grade that includes pond ciliates and a minority of serious parasites.
Familiarity 58