Key Area 2.7 Genetic control of metabolism

Question 1

What is a wild strain?

Answer 1

Wild strains are microorganisms that occur naturally.

Question 2

What is a mutation?

Answer 2

A change in DNA.

Question 3

What do mutations increase?

Answer 3

Genetic diversity.

Question 4

Are mutations always advantageous?

Answer 4

No usually mutations have a negative impact on the function of DNA but on rare occasions mutations can give an organism an advantage.

Question 5

What is mutagenesis?

Answer 5

Mutagenesis is the creation of mutations.

Question 6

How can the rate of mutagenesis be increased?

Answer 6

By exposing an organism to mutagenic agents.

Question 7

What is an example of a mutagenic agent?

Answer 7

UV-light and X-rays.

Question 8

What is a vector?

Answer 8

DNA used to carry foreign genetic material into another cell.

Question 9

What are some examples of vectors?

Answer 9

Plasmids and artificial chromesomes.

Question 10

What is recombinant DNA technology?

Answer 10

The transfer of genes from one species to another.

Question 11

What are the 2 enzymes used in recombinant DNA technology?

Answer 11

Restriction endonuclease and ligase.

Question 12

What does restriction endonuclease do in recombinant DNA technology?

Answer 12

It cuts the plasmid open and cuts the specific genes out of the chromosomes.

Question 13

Why must you use the same restriction endonuclease on both cuts?

Answer 13

To ensure that the sticky ends are complimentary.

Question 14

What does complimentary sticky ends mean?

Answer 14

The DNA sequence on the cut out gene is complimentary to the DNA sequence at the open plasmid.

Question 15

What does ligase do in recombinant DNA technology?

Answer 15

Seals the sticky ends together.

Question 16

What is a selectable marker gene?

Answer 16

A gene which is deliberately transferred along with the required gene during genetic engineering.

Question 17

Why is a selectable marker gene used?

Answer 17

To determine if the DNA sequence has been successfully inserted into the host organisms DNA.

Question 18

What is an example of a marker gene?

Answer 18

Antibiotic resistant gene.

Question 19

What is a regulatory sequence?

Answer 19

Sequences that control gene expression.

Question 20

What is the origin of replication?

Answer 20

A group of genes that allow self-replication of the plasmid/ artificial chromosomes.

Question 21

What is the use of the safety genes?

Answer 21

These are genes that ensure that the cell will not survive outside of the lab.

Question 22

Why is yeast used instead of bacteria in recombinant DNA technology?

Answer 22

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.