producing dna fragments

what is the name of the dna combined from two different organisms

recombinant dna

a genetic code being universal is evidence for what

indirect evidence for evolution

Gene transfer and cloning simple 5 stages

• isolation of dna fragments

• insertion of dna fragments into a vector

• transfer into suitable host cell

• identify using gene markers

• clone

methods of producing dna fragments

• creating gene in gene machine

• conversion of mrna to (complementary) dna using reverse transcriptase

• using restriction endonucleases to cut fragments containing desired gene from dna

reverse transcriptase is a form of

retrovirus

using reverse transcriptase process

• a cell that readily produces protein is selected

• large quantities of mrna so selected easily

• reverse transcriptase mrna-cdna (contains nucleotides that are complementary to mrna)

• dna polymerase is used to build up complementary nucleotides on cdna template

restriction endonucleases role

cuts a dna double strand at a specific base sequence called the recognition site. Leaving blunt ends. Cuts in staggered fashion to leave sticky ends (unpaired and exposed)

the recognition sequence is

palindromic

Gene machine process

• desired sequence of nucleotide bases for a gene is fed into a computer

• checked for biosaftey and if its ethical

• designs series of small, overlapping single strands (oglionucleotides), which is assembled into desired gene

• joined together (no introns)

• inserted into vector (plasmid)

advantage of gene machine

• any sequence of nucleotides can be produced in a short time

• accurate

• no introns so transcription can occur in prokaryotic cells