Module 6: Manipulating genomes

Question 1

True or False: Recombinant DNA technology involves the insertion of foreign DNA into a host organism’s genome.

Answer 1

True

Question 2

What is the term for a circular DNA molecule that can replicate independently of the chromosomal DNA?

Answer 2

Plasmid

Question 3

What is the name of the enzyme used to join DNA fragments together during DNA cloning?

Answer 3

DNA ligase

Question 4

What is the purpose of using a selectable marker in a plasmid during genetic engineering?

Answer 4

To identify cells that have successfully taken up the recombinant DNA

Question 5

What technique is used to amplify a specific DNA sequence in the laboratory?

Answer 5

Polymerase chain reaction (PCR)

Question 6

What is the name of the process used to separate DNA fragments based on their size using an electric field?

Answer 6

Gel electrophoresis

Question 7

What is the purpose of using a vector in genetic engineering?

Answer 7

To deliver foreign DNA into a host organism

Question 8

What is the name of the enzyme that synthesizes RNA from a DNA template during transcription?

Answer 8

RNA polymerase

Question 9

What is the term for the complete set of genes in an organism?

Answer 9

Genome

Question 10

Fill in the blank: In genetic engineering, the process of creating a DNA molecule by joining DNA fragments from different sources is called DNA ____________.

Answer 10

recombination

Question 11

What is the name of the technique used to cut DNA at specific sequences using a combination of restriction enzymes and DNA ligase?

Answer 11

Molecular cloning

Question 12

True or False: Genetic engineering techniques are used to manipulate the genetic material of organisms for various purposes.

Answer 12

True

Question 13

What is the term for a DNA sequence that codes for a specific protein?

Answer 13

Gene

Question 14

What is the name of the technique used to determine the sequence of nucleotides in a DNA molecule?

Answer 14

DNA sequencing

Question 15

What is the purpose of using a promoter sequence in genetic engineering?

Answer 15

To initiate transcription of the inserted DNA

Question 16

What is the name of the process used to create identical copies of a piece of DNA in a test tube?

Answer 16

DNA cloning

Question 17

Why is DNA polymerase called a thermos table enzyme?

Answer 17

It doesn’t denature at high temperatures.

Question 18

PCR (polymerase chain reaction) is used to …

Answer 18

Select a fragment of DNA (containing the gene you are interested in) and amplify it to produce millions in a few hours.

Question 19

Explain how PCR works.

Answer 19

1. Reaction mixture is set up with DNA sample, free nucleotides, primers and DNA polymerase.
2. DNA mixture is heated to 95 degrees C to break the hydrogen bonds. DNA polymerase doesn’t denature at this temp - many cycles of PCR can be carried out without having to use new enzymes each time.
3. Mixture is cooled to 50-60 degrees so primers can anneal (bind) to strands.
4. Reaction mixture is heated to 72 degrees C, so DNA polymerase can work. The DNA polymerase lines up free DNA Nucleotides alongside each template strand. Complimentary base pairing means new complementary strands are formed.
5. Two new copies of the fragment of DNA are formed and one cycle of PCR is complete, then the cycle starts again. Mixture heated to 95 degrees C and this time all 4 strands are used as template strands.

Question 20

Each PCR cycle …

Answer 20

Doubles the amount of DNA. 1 to 4 stands, to 8 strands.

Question 21

Explain how you can use restriction enzymes to get DNA fragment by PCR.

Answer 21

Some sections of DNA have palindromic sequences of nucleotides. Have antiparallel base pairs (base pairs read in opposite directions).