B14 - Variation Flashcards
Genetic variation
Differences between individuals that are inherited from parents
Natural selection
When the best adapted organisms are able to survive
‘Survival of the fittest’
Selective breeding
Involves people taking charge of selection to produce new varieties of species
Process of selective breeding
Decide which characteristics are most important
Choose parents that show these characteristics
Breed them together
Choose the best offspring from parents to breed the next generation
Repeat the process
Genetic engineering
Add, change or remove an organisms gene to alter it’s characteristics
Process of making insulin
A cell which can produce insulin is taken from a healthy human
The insulin gene is cut out of the human DNA using an enzyme
A plasmid is used to transfer the gene
The plasmid is removed from the bacteria and is cut open using an enzyme
The insulin gene is inserted into the plasmid using another enzyme
The plasmid with the insulin gene is taken up by bacteria so it can reproduce quickly
The insulin is then collected and ready for use
Cloning
When an organism has been produced by asexual reproduction and is genetically identical to its parents
Cloning in plants
Tissue sample scraped from parent cell
Placed in agar jelly
Grows in a petri dish
Placed in a compost to finish growing
OR
The tip of a plant is cut
You place it in a compost to let it grow
Cloning animals
A cell was taken from the udder of a sheep
An egg was taken from the ovary of a sheep
The nucleus was sucked out of the egg (enucleated)
The udder cell and the enucleated are fused together with electricity
Cell division occurs until an embryo is formed
The embryo is implanted into the female sheep
A calf is now born from the DNA of the male sheep
