1.2 - Domains of life

Question 1

What’s the evidence supporting the LUCA (last universal common ancestor) (3)

Answer 1

1. Biochemical components (L-Amino Acids + D-Carbohydrates)
2. Metabolic pathways
3. Universal genetic code

Question 2

What is 16s ribosomal RNA used for and why

Answer 2

• Used to understand relationship across all living organisms
• Due to slow rates of evolution in gene

Question 3

What are the 3 major organisms

Answer 3

1. Bacteria
2. Eukaryotes
3. Archaea

Question 4

What are the characteristics of Archaea (4)

Answer 4

• Single cell, prokaryotic, asexual microorganisms
• Lack of competition between archaea and bacteria
• ‘Extremophiles’
• Difficult to be cultured (studied via environmental DNA)

Question 5

Describe gastrointestinal archaea (3)

Answer 5

• Microbiota
• Found in oral cavity
• Non-pathogenic

Question 6

Describe endosymbiosis and primary endosymbiosis

Answer 6

• Symbiotic relationship where one organism lives inside the other
• (PE) original internalisation of prokaryotes (eg chloroplasts and mitochondria) by ancestral eukaryotic cell

Question 7

Recite the Linnean classification (don’t pick cocaine over fucking great surf)

Answer 7

• Domain
• Phylum
• Class
• Order
• Family
• Genus
• Species

Question 8

What are the rules for scientific nomenclature (2)

Answer 8

• 2 word scientific name (Genus-Species)
• Italics (Genus = capitalised, Species = lower case)