Recombinant DNA

Question 1

Recombinant DNA technology

Answer 1

Involves the introduction of foreign DNA into a cell, Genes from one organism are added to the chromosomes of another organism

Question 2

Potential of rDNA

Answer 2

Enormous potential to replace faulty genes with healthy genes, Cells used in rDNA can’t be reinserted into a human (would give them a disease) but is instead used to produce a certain protein which can be collected and given to humans (E.g insulin)

Question 3

Restriction enzymes

Answer 3

Able to cut up a piece of DNA, Cut the DNA from the donor genome to expose the gene of interest and cuts the DNA of the vector so that the gene of interest can be inserted

Question 4

Types of restriction enzymes

Answer 4

Sticky end (single ends, best), Blunt end

Question 5

Recognition site

Answer 5

Sequence of bases where the restriction enzyme always cuts

Question 6

Vectors

Answer 6

Bacteriophage or virus is used to transfer genetic material from one cell to another, E.g plasmids, viruses

Question 7

Role of vectors

Answer 7

Introduce desired genetic material to the host cell and increase the amount of desired DNA in the host cell

Question 8

Bacteriophages/phages

Answer 8

Rarely used for rDNA techniques, Viruses that infect bacterial cells, The viruses DNA is cut and the gene of interest is inserted into the virus’s DNA, Viruses are used as a vector to introduce genes to a cell’s DNA

Question 9

Plasmids

Answer 9

Circular strands of DNA found within bacteria, Capable of self-replication which is an advantage as it means plasmids hold more genetic information than a bacteriophage (amplifies amount of DNA available), Can be cut by a restriction enzyme and have the desired genes placed back into the bacteria

Question 10

DNA ligase (glue)

Answer 10

Enzyme that is capable of joining or recombining pieces of DNA

Question 11

Ligation

Answer 11

Process where pieces of DNA are joined together by DNA ligase

Question 12

rDNA main steps

Answer 12

Isolate the desired gene, Insert the gene into the vector and clone it, Large quantities of the vector are introduced to the selected host cell

Question 13

Production of insulin using rDNA

Answer 13

Identify the gene of interest (gene that codes for the protein insulin), Gene of interest is removed from the donor cell (beta cells in the islets of Langerhans in the pancreatic cell of a healthy person) using a restriction enzyme, Vectors (plasmid removed from bacterium) are cut using the SAME restriction enzyme, Gene is inserted into the plasmid and combined through ligation, Plasmid is reinserted back into the bacterium which undergoes mitosis, Bacterium (transgenic organism) produces large amounts of the protein and it is collected, Protein (insulin) can be bottled and later injected into people who have a faulty gene for that trait

Question 14

Transgenic organism

Answer 14

Any organism whose genome has been altered by the transfer of a gene or genes from another organism

Question 15

Function of transgenic organisms

Answer 15

Genetic engineering can create new organisms, Introduced genes become a part of the transgenic organism’s DNA and are then passed on to subsequent generations, E.g- jelly fish have a fluorescent genre which can be removed and inserted into a single-celled mouse embryo

Question 16

Production of factor VIII through rDNA

Answer 16

Identify and isolate the gene for factor VIII from a human liver cells using a restriction enzyme, Plasmid is removed from the bacterium and cut using the same restriction enzyme, Spliced plasmid and factor VIII gene join through ligase joining the sticky ends, Transgenic plasmid is placed into a mammalian cell and undergoes self-replication, Mammalian cell undergoes mitosis producing many plasmid containing cells capable of transcribing and translating the factor VIII gene in the plasmids, Large quantities of factor VIII are produced and is drained off, bottled and injected into haemophiliacs

Question 17

Vaccine production using rDNA

Answer 17

Identify and isolate the gene for the attenuated antigen from a pathogen using a restriction enzyme, Use the same restriction enzyme to cut the plasmid that has been removed from bacterium, Spliced plasmid and antigen gene sticky ends are joined together through ligation, Transgenic plasmid is placed into yeast cell and undergoes self-replication, Yeast cell undergoes mitosis producing many plasmid containing cells capable of transcribing and translating the antigen gene in the plasmids, Large quantities of the attenuated antigen are produced through transcription and translation of the gene and is drained off, bottled and used to vaccinate people

Question 18

Production of human growth hormone using rDNA

Answer 18

Identify and isolate the gene for HCG production from a human pituitary cell using a restriction enzyme, Use the same restriction enzyme to cut the plasmid that has been removed from bacterium, Spliced plasmid and HCG gene sticky ends are combined through ligation, Transgenic plasmid is replaced into bacterium and undergoes self-replication, Transgenic bacterium undergoes mitosis producing many transgenic bacteria capable of transcribing and translating the HCG gene , Large quantities of human growth hormone are produced through transcription and translation of the HCG gene which is then drained off, bottled and injected into people who are producing too little of their own hormone