This topic summary covers Knowledge Organiser within Classification for GCSE Biology. Classification systems, taxonomy, and evolutionary relationships It is section 10 of 11 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 11
Practice
25 questions
Recall
20 flashcards
Knowledge Organiser
Taxonomic Hierarchy
- Kingdom — broadest group
- Phylum
- Class
- Order
- Family
- Genus
- Species — most specific group
- Mnemonic: Kings Play Chess On Fine Green Silk
Three Domains (ABE)
- Archaea — ancient, extreme environment prokaryotes
- Bacteria — true bacteria, prokaryotes
- Eukaryota — animals, plants, fungi, protists
- Proposed by Carl Woese using rRNA analysis
- Replaced five-kingdom system
Binomial Naming Rules
- Two parts: Genus + species
- Genus: capital letter first
- Species: all lower case
- Italicised when typed, underlined when written
- Examples: Homo sapiens, Felis catus, Panthera leo
Why Classification Changes
- New evidence emerges (DNA, RNA analysis)
- Molecular evidence more reliable than morphology
- Woese used rRNA to reveal Archaea as a distinct domain
- Classification reflects evolutionary relationships
- Species: can interbreed to produce fertile offspring