What it does
Biologists place every species in a set of nested groups called ranks. From the biggest to the smallest:
Kingdom → Phylum (Division for plants) → Class → Order → Family → Genus → Species
Each step down holds fewer organisms that are more alike. The species name is a binomial: the genus plus one more word, such as Panthera tigris for the tiger or Mangifera indica for the mango.
This page draws that hierarchy as a ladder for two organisms at once. Where both have the same name on a rung, the rung is joined across the middle; where they part, the ladder splits in two. So you can see straight away how closely two organisms are related: a tiger and a lion stay together down to the genus Panthera; a house cat and a dog only to the order Carnivora; a human and a mango not even at the first rung.
It fits the Class 11 biology chapter on the living world (taxonomic categories and the hierarchy), and the Class 9 chapter on diversity. Sort organisms into kingdoms first with the five-kingdom sorter game, and into animal phyla with the animal classification key.
How to use it
- Pick an organism for the Left and Right columns.
- The title names the lowest rank they share. Shared rungs sit in the shaded box in the middle; below the split, each column shows its own names.
- The line under the ladder says how close that makes them (same order: fairly close; same family: close; same genus: very close).
- Put the ranks in order: tap the seven rank names from kingdom down to species. A wrong tap tells you whether that rank is lower down or already placed. Shuffle again starts a new round.
Worked example
The page opens with the tiger on the left and the house cat on the right. The title reads “Tiger and House cat share down to the family: Felidae”. The shaded box covers Animalia, Chordata, Mammalia, Carnivora and Felidae; then the ladder splits: genus Panthera and Felis, species Panthera tigris and Felis catus. The note says “Same family: close relatives.”
Change the right column to Lion: now even the genus is shared (Panthera), and only the species differs (Panthera leo).
Tips
- A handy way to remember the order: King Philip Came Over For Good Soup.
- Animal family names end in -idae (Felidae, Hominidae); plant family names end in -aceae (Poaceae, Anacardiaceae).
- Write a scientific name with a capital letter for the genus and a small letter for the species epithet, in italics (underline it when handwriting).
FAQ
Why do the plants say Dicotyledonae and Monocotyledonae? That is the class level used in school biology. Modern plant classification (based on DNA) uses different groups above the order, but the order, family, genus and species shown here stay the same.
Is a dog Canis familiaris or Canis lupus familiaris? Both are used. Many biologists treat the dog as a subspecies of the wolf; school books usually write Canis familiaris.
Is anything stored? No. Everything runs in your browser. fibub is not part of NCERT; the topics follow the syllabus, but the words and examples are our own.
Where the numbers come from
- The taxonomic ranks and the classifications of the twelve organisms are standard biology (for plants, the dicot/monocot classes still used in school). The ladder, its wording and the choice of organisms are fibub's own; no textbook text, figures or tables are copied.
Standard scientific values, such as constants, atomic weights and melting points, are facts found in every textbook; we name where ours were checked. If you are an author or publisher and want a value, a credit or a table changed or removed, tell us and we will act quickly.
Last updated 2026-11-09.