Evolution and Genetic Engineering Flashcards
fathers of evolution
charles darwin
alfred wallace
observations of the theory of natural section
overbreeding: organisms produce a large number of offspring
population numbers stay constant: numbers reach the max. the environment can support
inherited variations occur: no two members of the same species ever look alike (except identical twins)
conclusions of the theory of natural selection
struggle for existence: overbreeding leads to competition within species for food, water, mates
survival of the fittest: variation occurs within species and the better adapted members are more likely to survive and leave more offspring
these survivors will pass on their better genes to their offspring, who will also show this beneficial variation
natural selection
variation occurs within species and members of a species with genetic traits that allow them to be better adapted to survive in their environment will reproduce and pass these on to following generations ie survival of the fittest
evolution
inheritable change within a population in response to changes in the environment or over time, giving rise to new species
evidence of evolution: source
the study of fossils
fossils as evidence of evolution
can be aged and compared on a timescale
can be compared with modern organisms
can be linked to environmental change
example of a fossil use
the anatomy of a horse
size increased over time from 0.4m 60 million years ago to 1.6m today
stages of genetic engineering
isolation cutting ligation cloning expression
isolation (GE)
target gene from donor is identified and removed
plasmid DNA from bacterium removed (acts as a vector)
cutting (GE)
DNA and plasmid cut at specific sites using restriction enzymes
ligation
target gene inserted into plasmid using DNA ligase to join it together = recombinant DNA
transformation: recombinant DNA introduced into bacterial cell
introduction of base sequence changes: the sequence of bases in the host is now different
cloning (GE)
bacteria reproduce asexually by binary fission, produce many identical copies of themselves containing recombinant DNA
expression (GE)
the gene causes the production of a protein (product)
application of GE in plant
herbicide resistant crops
inserting a bacteria gene for herbicide resistance in crop plants, so that when the herbicide is sprayed it will kill weeds not plant
