Biotechnology: Unit 4, Topic 1

Question 1

What is recombinant DNA? What are the process of DNA recombination?

Answer 1

• combines DNA from different sources to generate a modified DNA sequence (transfer a gene from the cell of one species to the cell of a different species)
• series of techniques used to manipulate and isolate DNA segments of interest

Process of making recombinant DNA:
1. isolation of gene of interest - restriction enzymes are used to isolate the gene and cut the plasmid. (restriction enzymes cut DNA into smaller pieces are specific sites). Creates 2 sticky ends
2. insertion of the isolated gene into a vector - plasmids (circular pieces found in bacteria) are used as vectors to transport the gene of interest into bacterial cells. (a vector needs to be used because if the DNA was inserted directly into the cell, it may be perceived as foreign material and destroyed.
3. Joining of the transferred fragment and another - DNA ligase joins DNA fragment and plasmid.
4. Application of recombinant DNA - the recombinant plasmids are added to a bacterial culture. the recombinant DNA will now also be replicated within the bacteria

Question 2

What is the applications of DNA sequencing?

Answer 2

DNA sequencing -> determining the nucleic acids sequence

DNA profiling -> process of determining an individual’s DNA characteristics; can be used to identify a species or individual (crimes, to identify murder, investigates relatedness between individuals)

applications include:
- gene cloning (recombinant DNA processes)
- replicating organic molecules for research and treatment of conditions
- introducing pest resistance into some plants
- as a vector for gene therapy

Question 3

What is Polymerase Chain Reaction (PCR)?

Answer 3

• amplify, or make millions of copies of a specific sequence of DNA
• carried out by an automated machine called a thermal cycler -> used DNA polymerase to catalyse the formation of new DNA molecules by joining together free nucleotides
• can be used for crime scnee analysis
• purpose of PCR is to replicate DNA sequences for analysis.

Question 4

What is Gel Electrophoresis?

Answer 4

• a technique that separates fragments of DNA or other macromolecules, such as RNA and proteins, according to their size and charge.
• molecules are pushed by an electrical field through the gel.