manipulating genomes

Question 1

DNA polymerase

Answer 1

An enzyme that synthesises new DNA.

Question 2

Restriction enzyme

Answer 2

An enzyme that cuts DNA at specific sequences.

Question 3

DNA ligase

Answer 3

An enzyme that reseals cut ends of DNA.

Question 4

Plasmids

Answer 4

Small circular pieces of DNA found in bacteria that have antibiotic resistance genes.

Question 5

Reverse transcriptase.

Answer 5

An enzyme found in some viruses with an RNA genome, this enzyme converts RNA into DNA.

Question 6

Bacteria can be genetically modified to produce human insulin. mRNA that codes for insulin is extracted from human pancreas cells.
What needs to be done with the mRNA in order for the rest of the genetic modification to be completed?

Answer 6

• Use reverse transcriptase to get single stranded complementary DNA from the mRNA.
• Then use DNA polymerase to make the DNA double stranded.

Question 7

One valid concern that people have about genetic modification of bacteria.

Answer 7

It can become antibiotic resistant.

Question 8

To produce DNA profile, DNA first needs to be purified. Explain why a protease enzyme is added to the mixture during the DNA purification process.

Answer 8

To break down the histone proteins and hat the DNA is wrapped around.

Question 9

What is the name of the enzyme used in PCR to synthesise new DNA strands?

Answer 9

Taq/DNA polymerase

Question 10

Changes that would improve electrophoresis.

Answer 10

• Use an alkaline buffer solution over the gel, which the current can pass through so the DNA fragments can separate.
• Use a marker. For example, a fluorescent marker that fluoresces under UV light so that you can see the bonding pattern of the DNA fragments.

Question 11

Difference between somatic gene therapy and germ line gene therapy.

Answer 11

Somatic - where you replace the unhealthy genes with the heathy ones. They are inserted to normal body cells and cannot be passed onto offspring to be inherited.
Germ line - when you insert new genes into germs ones. They are inserted into gametes (e.g fertilised egg/sperm) be inherited onto offspring.

Question 12

Define DNA sequencing.

Answer 12

Determining the sequence/ order of bases in a DNA molecule.

Question 13

Development that has led to an increase in the speed at which DNA can be sequenced.

Answer 13

• High throughput sequencing.
• nanopore technology.

Question 14

Explain how DNA sequencing allows the sequence of amino acids in a polypeptide to be predicted.

Answer 14

You can determine the order of bases that code for an amino acid. Each triplet of bases codes for an amino acid.

Question 15

How can sequencing be used to increase effectiveness of a vaccination programme against ebola?

Answer 15

DNA sequencing finds the order of bases.
Ebola has a high mutation rate, meaning many strains can form.
Sequencing can be used to find the new strains. You can compare with old.
You can find the correct antigen to use in the vaccine.

Question 16

How can bioinformatics be used to increase effectiveness of a vaccination programme?

Answer 16

Use of computer software to analyse and store biological data about DNA, RNA and proteins . Data is universal and shared internationally. Information of where disease started can be accepted by scientists so they can vaccinate these vulnerable areas.