Model Organims Flashcards
why do we use model organisms
there are ethical concerns about experimenting on people
since science is reductionists in nature, we often look at simpler examples to understand complex processes
what are the different types of commonly used model organisms
-bacterial culture
-yeast
-C elegans
-drosphola
-zebrafish
-xenopus
-human cell cultures
-axolotl
-mice
what are the pros and cons of bacterial cultures
PROS:
-easy to genetically modify
-grow very rapidly
-easy to grow and culture
CONS:
-very far detached from human cells
-prokaryotic
-no post translational modification
-always unicellular
what are the pros and cons of yeast cells
PROS:
-eukaryotic
-easy to culture
-genome has been fully sequenced
-easy to modify
CONS:
-unicellular
What are the pros and cons of C elegans
PROS:
-cell fates have been completely mapped
-genome has been completely sequenced
-multicellular
-transparent
-eukaryotic
-easy and cheap to keep and maintain
CONS:
-invertebrate
-not all organs are present
What are primary human cell cultures
these colonies will die after a certain number of devisions
what are immortalised human cell cultures
these will not dies after they have decided a certain number of times. They were originally derived from cancer cells.
what are the pros and cons of human cell cultures
PROS:
-eukaryotic, human cells
-wide range of tools available to manipulate the culture
-no ethical concerns despite cells being human
CONS:
-effectively unicellular
-demanding to grow
what are the pros and cons of drosophila
PROS:
-huge bank of knowledge
-fully sequenced genomes
-easy to genetically manipulate
-eukaryotic and multicellular
-easy and cheap to keep and maintain
CONS:
-invertebrate
-embryos are very small and hard to handle
what are the pros and cons of zebrafish
PROS:
-sophysticated multicellular eukaryote
-lots of well characterised mutations
-vertebrate
-fully sequenced genome
-embryoes are large and develop externally to mother
what are the pros and cons of Xenopus
PROS:
-tadpoles provide a simplified organism
-multicellular eukaryotic vertebrate
-embryoes are large and easy to work with
-lay lots of eggs per lay
-embryoes develop outside the mother (frogspawn)
CONS:
-xenopus laevis are tetraploid
-genome is not fully sequenced
-limited resources compared to drosophila
why are axolotls sometimes used as model organisms
axolotls have the ability to regrow limbs. this has lots of medical implications so is an area of research.
However since it is very niche there are not a lot of resources on manipulating axolotls
