Classification and Evolution

Question 1

Classification

Answer 1

The sorting of organisms into groups

Question 2

Species

Answer 2

A group of organisms that can interbreed to produce fertile offspring

Question 3

Taxonomic groups (8)

Answer 3

1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species

Question 4

Advantages of a classification system

Answer 4

Enables scientists to:

• Analyse evolutionary relationships between organisms
• Predict characteristics (as species grouped together are likely to share characteristics)
• Share research findings (without confusion or ambiguity)

Question 5

Prokaryotae

Answer 5

• 1/5 kingdoms
• Unicellular
• Domain: Bacteria and Archaea
• No organelles present
• Cell wall of peptidoglycan/murein
• Autotrophic or heterotrophic

Question 6

Protoctista

Answer 6

• 1/5 kingdoms
• Unicellular or multicellular
• Domain: Eukarya
• Has organelles present
• No cell wall
• Autotrophic or heterotrophic

Question 7

Fungi

Answer 7

• 1/5 kingdoms
• Unicellular or multicellular
• Domain: Eukarya
• Has organelles present
• Chitin cell wall
• Saprotrophic (extracellular digestion)

Question 8

Plantae

Answer 8

• 1/5 kingdoms
• Multicellular
• Domain: Eukarya
• Has organelles present
• Cellulose cell wall
• Autotrophic

Question 9

Animalia

Answer 9

• 1/5 kingdoms
• • Multicellular
• Domain: Eukarya
• Has organelles present
• No cell wall
• Heterotrophic

Question 10

Why have domains been introduced?

Answer 10

Woese’s domain classification:

• Bacterial cell walls contain peptidoglycan but those of Archaea do not
• The RNA Polymerase of Archaea contains 8-10 subunits, but bacterial RNA Polymerase contains only five subunits
• Archaea have rRNA that is different to the rRNA of Bacteria and Eukarya