Selective Breeding
breeding organisms with desirable traits
Hybridization
crossing different individuals to bring out the best of both organisms
Inbreeding
crossing individuals with similar characteristics
Inbreeding Pros
breeds are maintained and unique characteristics are kept
Inbreeding Cons
increased susceptibility to disease and deformities
how to increase mutations
exposing organisms to radiation or chemicals, but many will die
manipulating DNA steps
extract DNA from cells, cut it into small pieces, identify sequences of bases, make copies
creating recombinant DNA steps
extract human DNA
isolate human gene for insulin using a restriction enzyme (EcoRI)
enzyme cuts DNA at a specific sequence
creates sticky ends: single strands of DNA that are produced from the restriction enzyme
extract ring of DNA, plasmid, from bacterial cell
cut plasmid using restriction enzyme (EcoRI), creating complimentary sticky ends
human gene and plasmid are combined with DNA Ligase
insert recombinant DNA into bacterial cell
gene cloning through recombinant plasmid steps:
treats plasmid and gene coding for a protein (gene P) with an enzyme that cuts DNA
enzyme cleaves plasmid
plasmid and trarget gene DNA are mixed
DNA ligase joins them together with covelent bonds
recombinant plasmid containing targeted gene is mixed with bacteria
bacterium takes up plasmid DNA through transformation
recombinant bacterium reproduces to form a clone of cells containing desirable gene
Genomic library storage:
a collection of cloned DNA fragments that include an organism’s entire genome
Reverse Transcriptase Steps
chosen cells transcribe genes
process transcripts: remove introns
isolate mRNA in a test tube
single stranded DNA transcripts are made from mRNA using reverse transcriptase ( viral enzyme that synthesizes DNA from RNA template
another enzyme is added to break down mRNA
DNA polymerase synthesize a second DNA strand
results: complementary DNA (cDNA)
only subset of genes that’s transcribed into mRNA in starting cells.
cDNA library is useful for studying genes responsible for specialized functions of a particular cell type
Recombinant DNA
when scientists combine pieces of DNA from two different sources to make one molecule; used for genetic engineering
Bacterial Plasmids
DNA molecules that replicate separately from a larger chromosome, only carry a few genes, easily manipulated to carry any gene, is a vector
Vector
a particle that can carry foreign genes
Polymerase Chain Reaction
rapidly make lots of copies of specific DNA sample
take small sample of DNA and amplify it to a large enough amount to study in detail
Gel Electrophoresis
dna fingerprinting
identify individuals by DNA characteristics
uses gel and electricity
used to separate and analyze macromolecules (dna rna proteins) based on size and electrical charge
transgenic organisms
contain genes from other organisms (GMO’s)
Microorganism
bacteria
transgenic animals
used to study genes and improve supply
dna cloning steps
harvest somatic cells and extract the nucleus for cloning
extract donor egg and remove nucleus
inject cloning nucleus into donor egg for a new egg cell
new cell divides in mitosis and forms embryo
implant new formed embryo into surrogate mother