Model Organisms

Question 1

Characteristics of a good model organisms to investigate bio processes

Answer 1

1. Small size, genome and simple nutrient requirements
2. Rapid life cycle producing large numbers of progeny
3. Easy to genetically modify, with multiple mutants available to study

Question 2

Give examples of proteins that GM E.coli carry within its plasmids

Answer 2

1. Insulin to treat diabetes
2. Erythropoietin to treat anemia
3. Growth hormone to treat growth disorders

Question 3

What makes yeast a useful model organism

Answer 3

1. Simplest unicellular eukaryotic organism
2. Easy to genetically modify
3. Contains plasmids that are compatible with bacterial plasmids
4. Exists in diploid AND haploid forms useful for studies
5. Shares many proteins with humans
6. Genes coding for proteins are folded and glycosylated correctly in yeast, not in E.coli
7. Good for studying why mutant forms of proteins can lead to disease e.g. mutant huntingtin protein

Question 4

Why is c.elegans a good model organism

Answer 4

1. Abundant
2. Small and only need E.coli as food
3. Short generation time (3 days)
4. Easy to genetically manipulate via DNA injection
5. Females are hermaphrodite lol
6. Transparent body
7. Highly predictable (stereotypic) growth and development

Question 5

Why are drasophila a good model organism

Answer 5

1. Small and rapid life cycle of 10 days
2. Easy to genetically modify by DNA injection into embryos
3. Many mutants
4. Every gene can be modified
5. 50% genes in common with humans so most genes involved in disease also cause disease in drasophila
6. Disease models for cancer, MND, Alzheimer’s, Parkinson’s,

Question 6

Why are mus muscularis good model organisms

Answer 6

1. Small and easy to house in cages
2. 8 week generation time with large litters 8-10
3. Similar genome to humans
4. Easy GM by injection into cells + implantation
5. Many mutants
6. Good disease model

Question 7

Thale-cress plant reasons why - the same waffle

Answer 7

1. Abundant weed, rapid growth and generation time of 6 weeks
2. Self fertilises but can be crossed with other plants
3. Mutants available and easy to GM using a soil bacterium
4. Small genome for plant
5. in biotech an Arabidopsis gene increases phenol production in food (flavanols good for cardiovascular health)
6. Salt-tolerant tomato plants use the arabidopsis gene that shuttle Na+ into central vacuole