L7 Model Organisms Flashcards
A good model organism possesses the following characteristics (5)…
- Rapid maturation
- Easy manipulation
- Readily available
- Short life cycle
- High fecundity
Genetic characteristics of a good model organism are (4)…
- Possible to make large scale genetic crosses
- range of mutants available
- transformable
- sequenced genome available
E.Coli is well established model organism. However, its main shortcoming is that it is not…
a eukaryote ☹
Define: homologue (genetics)
A gene related to another gene by descent from a common ancestral DNA sequence
Define: orthologue
Homologous genes with similar functions in a different species
Define: Paralogue
Homologous genes related by duplication within the same genome
Define: gene knockout
The complete or partial removal of gene, resulting in complete elimination of expression 🥊
Define: gene knockdown
Techniques reducing gene expression (such as RNA interference, morpholinos)
A mutant organism that mimics the phenotype or features observed in human disease is known as a…
Disease Model
40% of genes in ? have human orthologues
C. elegans
C. elegans has been useful in understanding ageing and development due to the fact that it has…
An exact number of cells in a fixed position (thus they can be tracked through development)
The advantage of using zebrafish instead of mice 🐁 in drug discovery is…
Zebrafish are cheaper 💰🐠
Define: transgenic animal ❓
An animal the cells of which contain DNA from another organism
Advantages of yeast as a model organism (4)
- large scale crosses
- many mutants
- easily transformable with plasmids
- easy gene knockout
Advantages of Drosophila melanogaster as a model organism (4)
- easy to cross
- huge variety of mutants
- transformable by p element transposon
- tissue specific knockdowns possible
Advantages of C. elgans as a model organism (4)
- easy to cross
- many mutants
- transformable
- knockdown by RNA interference
Advantages of zebrafish as a model organism (4)
- sturdy, micro-injectable embryos that can develop externally
- transparent embryos 👻
- Knockdown with morpholinos
- Cheaper than mice
Advantages of mice as a model organism (5)
- many orthologues
- high fecundity for a mammal
- knockouts and tissue specific knockouts
- can be inbred to produce identical offspring
- many disease models available & prone to similar diseases as humans
Disadvantages of using mice as model organisms (3)
- Very expensive
- Time consuming
- Ethical issues
