Dna Technology

Question 1

What is recombinant DNA tech

Answer 1

Transfer of DNA from one organism to another

Question 2

What is the first step in DNA tech

Answer 2

Isolate the gene required
This can be done through conversion of mRNA to complementary DNA using reverse transcriptase
Using restriction enzymes to cut fragment containing the desired gene from DNA
Creating the gene in a gene machine

Question 3

How do you use reverse transcriptase in DNA tech

Answer 3

• mRNA is mixed with free DNA nucleotides and enzyme reverse transcriptase
• free DNA nucleotides bind to single stranded mRNA via complementary base pairing
• reverse transcriptase joins DNA nucleotides together to form a single stranded DNA strand copy of mRNA template called cDNA
• the addition of further DNA nucleotides and DNA polymerase is then used to make cDNA double stranded

Question 4

What are the advantages of using reverse transcriptase

Answer 4

• cells contain many mRNA for genes they are expressing the gene ( many copies )
• using mRNA means introns have been removed ( prokaryotes can’t express introns )

Question 5

What are the disadvantages of reverse transcriptase

Answer 5

mRNA does not contain promoter and terminator regions of the target DNA sequence, so these have to be added to any cDNA produced before the gene can be expressed during in vivo techniques