2.4 Model systems

Question 1

Model systems

Answer 1

E.Coli

• small genome - 4.6 million base pairs
• divide every 20 minutes

Yeasts (e.g. saccharomyces cerevisiaw)

• simplest eukaryotic cells
• 12 milllion base pairs
• divide every 2 hours

Question 2

Invertebrate models

Answer 2

Caenorhabditis elegans

• multicellular eukaryotes
• smaller genome than most animals : 100 million base pairs
• 19 000 genes

Drosophila melanogaster
- short reproductive cycle - 2 weeks

Question 3

Vertebrae models

Answer 3

Xenopus laevis

• eggs are 1 mm
• large quantities
• develop externally

Danio rerio

• 3 - 4 month generation time
• embryos develop outside mother