The Living World
Class 11 · Biology
4 ideas in Class 11 Biology, explained in plain words, with games and quizzes to practise.
Diversity and Nomenclature
Part of: Naming and Ordering Life
Known species number near 1.8 million and keep growing. One global name per organism avoids local-name chaos. Linnaeus paired genus with epithet: capitalised genus, small epithet, Latinised, with the author's mark at the end.
Why it matters. Shared names let the world study the same organism. Rules keep every name unique and traceable.
Key words
- Biodiversity
- : The variety of living organisms on Earth, with about 1.7 to 1.8 million known species.
- Nomenclature
- : The system of giving each organism one standard scientific name accepted worldwide.
- Binomial nomenclature
- : The two-word naming system giving every species a genus name plus a specific epithet.
- Genus
- : The first word of a scientific name, grouping closely related species and written with a capital.
- Specific epithet
- : The second word of a scientific name, identifying one species and written in small letters.
Try it in two minutes
- Count species named in your area.
- Write mango's name by the rules.
- Spot the genus and epithet in three names.
Try at home. List local versus scientific names of five plants.
Taxonomy, Systematics and Identification
Part of: Naming and Ordering Life
Characterisation describes, identification names, classification groups, nomenclature labels. Taxa are ranked categories; systematics adds evolutionary kinship to the arrangement. Early sorting served uses; modern work adds cells, development and ecology.
Why it matters. Four processes in order stop taxonomy blurring into one word. Kinship turns lists into family trees.
Key words
- Taxonomy
- : The science of identifying, naming and classifying organisms into ordered groups.
- Systematics
- : The study that arranges organisms by evolutionary relationships along with likeness.
- Identification
- : The process of finding the correct name of an organism by comparison with known records.
- Taxon
- : Any named unit of classification, such as a species, genus or family.
- Characterisation
- : The careful description of an organism's features before it is named or grouped.
Try it in two minutes
- Describe a pet fully.
- Match it to its name.
- Place it among mammals.
Try at home. Classify kitchen items by use, then by material.
Taxonomic Hierarchy: Species to Kingdom
Part of: Ranks and Reference Tools
Species is the lowest rank; genus groups related species; family, order, class, phylum and kingdom rise above. Lion and tiger share Panthera; potato and brinjal share Solanum; humans are Homo sapiens.
Why it matters. The ladder places every organism in nested homes. Shared ranks reveal true closeness.
Key words
- Species
- : The lowest rank of classification, holding organisms that share the most characters.
- Genus
- : The rank above species that gathers closely related species, as Panthera does for lion and tiger.
- Family
- : The rank above genus that gathers related genera sharing common features.
- Order
- : The rank above family that groups related families by shared characters.
- Kingdom
- : The highest rank of classification, holding many related phyla together.
Try it in two minutes
- Order seven ranks bottom to top.
- Group lion with tiger.
- Name three shared genera.
Try at home. Place mango, lion and human on the ladder.
Taxonomical Aids
Part of: Ranks and Reference Tools
Herbaria store dried plants; museums preserve animal specimens; gardens grow living plants; zoos house living animals. Keys sort by paired contrasts; floras, manuals and monographs keep descriptions for matching.
Why it matters. Aids hold the evidence behind every name. Keys and books let anyone recheck an identification.
Key words
- Herbarium
- : A store of dried, pressed and labelled plant specimens kept for identification.
- Botanical garden
- : A living collection of plants grown for study, conservation and display.
- Museum
- : A place preserving animal specimens, skeletons and eggs for study and reference.
- Zoological park
- : A place where live wild animals are kept for study, conservation and viewing.
- Key
- : A step-by-step tool of paired choices that leads to the name of an organism.
Try it in two minutes
- Press a leaf for a sheet.
- Label it fully.
- Key it with contrasts.
Try at home. Make a home herbarium sheet of one leaf.
What your child will practise
- Diversity and Nomenclature: Candy Puzzle (Clue Puzzle)
- Diversity and Nomenclature: Candy Quick Fire (Quick Fire)
- Taxonomic Hierarchy: Species to Kingdom: Desert Puzzle (Clue Puzzle)
- Taxonomical Aids: Jungle Quest (Flip and Match)
- Taxonomy, Systematics and Identification: Ocean Quick Fire (Quick Fire)
- Quiz: Diversity and Nomenclature (8 questions)
- Quiz: Taxonomic Hierarchy: Species to Kingdom (8 questions)
- Quiz: Taxonomical Aids (8 questions)
- Quiz: Taxonomy, Systematics and Identification (8 questions)