DNA Fragmenting

Question 1

What does recombinant DNA technology involve?

Answer 1

The transfer of fragments of DNA from one organism species to to another.

Question 2

State why transfer of DNA between organisms is possible.

Answer 2

Genetic code is universal

Question 3

What are transgenic organisms?

Answer 3

An organism or cell whose genome has been altered by the introduction of one or more foreign DNA sequences from another species by artificial means. (Also known as GMOs)

Question 4

As genetic code is universal, this can allow which process to happen in transgenic organisms?

Answer 4

Translation of transferred DNA

Question 5

Name a protein produced in large volumes by recombinant DNA technology.

Answer 5

Insulin

Question 6

Name the 5 stages of producing a protein by DNA technology.

Answer 6

1. Isolation of DNA
2. Insertion of DNA into vector
3. Transfer of DNA to hosts
4. Identification of hosts
5. Growth/cloning of hosts

Question 7

Which stage of producing proteins by DNA technology is DNA fragmenting?

Answer 7

1, isolation of DNA

Question 8

What does c in cDNA stand for?

Answer 8

Complementary

Question 9

Name the enzyme that converts mRNA to cDNA.

Answer 9

Reverse transcriptase

Question 10

What are and what do restriction endonucleases do?

Answer 10

They are enzymes that cut the sugar phosphate backbone of DNA at a specific recognition or restriction site.

Question 11

What is a primer?

Answer 11

A short strand of DNA synthesised to be complimentary to a sequence of nucleotide bases at the ‘3 end of the DNA.

Question 12

What does mRNA act as when forming cDNA?
Why?

Answer 12

A template
The nucleotides used to make the cDNA are complimentary to the mRNA

Question 13

Once the primer and DNA nucleotides are added to the medium containing cDNA, where will they move/line up?
How does this lead to production of the DNA strand? Name the enzyme used.

Answer 13

They would line up opposite the complementary bases on the cDNA strand.
This acts as the point of attachment for the DNA polymerase to begin to assemble the nucleotides to form the new strand.

Question 14

Why are restriction enzymes used by bacteria and archaea?

Answer 14

For protection against phage viruses

Question 15

How do restriction enzymes protect bacteria against viruses?

Answer 15

They cut DNA which prevents viruses from making copies of themselves.

Question 16

Explain why b cells from the Islets of Langherans are used to synthesise insulin.

Answer 16

They produce large amounts of mRNA that codes for the protein which can be isolated and used to produce cDNA.

Question 17

What are blunt ends and how are they formed?

Answer 17

Blunt ends are formed when restriction endonucleases make straight cuts through the DNA. This means that DNA fragments are straight.

Question 18

What are sticky ends and how are they formed?

Answer 18

Sticky ends form when the restriction endonuclease cuts in a staggered fashion, leaving uneven cuts with bases exposed at either end of the molecule

Question 19

What is a palindrome?

Answer 19

Base sequences that read opposite to each other.

Question 20

What is a gene machine?

Answer 20

The use of bioinformatics to synthesise a specific gene

Question 21

Why is the biosafety of genes checked before synthesising the gene?

Answer 21

Ethical reasons

Question 22

What is ssDNA?

Answer 22

Single stranded DNA

Question 23

What is an oligonucleotide?

Answer 23

A polynucleotide whose molecules contain a relatively small number of nucleotides.

Question 24

Describe how oligonucleotides are joined together in a gene machine?

Answer 24

They are joined by DNA polymerase.

Question 25

What type of section of DNA is not present in oligonucleotides?

Answer 25

Introns