Key Area 2.7 Genetic control of metabolism Flashcards
What is a wild strain?
Wild strains are microorganisms that occur naturally.
What is a mutation?
A change in DNA.
What do mutations increase?
Genetic diversity.
Are mutations always advantageous?
No usually mutations have a negative impact on the function of DNA but on rare occasions mutations can give an organism an advantage.
What is mutagenesis?
Mutagenesis is the creation of mutations.
How can the rate of mutagenesis be increased?
By exposing an organism to mutagenic agents.
What is an example of a mutagenic agent?
UV-light and X-rays.
What is a vector?
DNA used to carry foreign genetic material into another cell.
What are some examples of vectors?
Plasmids and artificial chromesomes.
What is recombinant DNA technology?
The transfer of genes from one species to another.
What are the 2 enzymes used in recombinant DNA technology?
Restriction endonuclease and ligase.
What does restriction endonuclease do in recombinant DNA technology?
It cuts the plasmid open and cuts the specific genes out of the chromosomes.
Why must you use the same restriction endonuclease on both cuts?
To ensure that the sticky ends are complimentary.
What does complimentary sticky ends mean?
The DNA sequence on the cut out gene is complimentary to the DNA sequence at the open plasmid.
What does ligase do in recombinant DNA technology?
Seals the sticky ends together.
What is a selectable marker gene?
A gene which is deliberately transferred along with the required gene during genetic engineering.
Why is a selectable marker gene used?
To determine if the DNA sequence has been successfully inserted into the host organisms DNA.
What is an example of a marker gene?
Antibiotic resistant gene.
What is a regulatory sequence?
Sequences that control gene expression.
What is the origin of replication?
A group of genes that allow self-replication of the plasmid/ artificial chromosomes.
What is the use of the safety genes?
These are genes that ensure that the cell will not survive outside of the lab.
Why is yeast used instead of bacteria in recombinant DNA technology?
Eukaryotic cells DNA contains both introns and exons but bacteria cells only contain introns, this means that proteins may be inactive because the bacteria cannot fold the polypeptide chain from eukaryotic organisms.
