D1.1 DNA Replication

Question 1

Define DNA replication

Answer 1

Production of exact copies of DNA with identical base sequences.
– needed for reproduction, growth and, tissue repair

Question 2

What is semi-conservative nature?

Answer 2

• There are two DNA molecules composed of a pre-existing strand and a newly synthesized strand.
• Ensures there is genetic continuity with a high degree of accuracy between generations of cells.

Question 3

What is the role of helicase and DNA polymerase in DNA replication?

Answer 3

1. Helicase: Unwinds the DNA double helix and separates the two strands by breaking hydrogen bonds, into the template and coding strand.
2. DNA polymerase:

• Links free nucleotides with the nitrogenous bases on the template strand forming hydrogen bonds between complementary bases.

Question 4

What is polymerase chain reaction? (incl. Taq Polymerase)

Answer 4

Polymerase chain reaction (PCR) amplifies small DNA fragments by adding DNA polymerase which catalyzes the DNA replication process.
The solution must be heat up at high temperatures. However, because enzymes may denature at extremely high temperatures, Taq DNA polymerase is used because it is heat-resistant therefore, will not denature at high temperatures.

Question 5

Applications of polymerase chain reaction and gel electrophoresis

Answer 5

1. Testing for coronavirus
2. Paternity testing

Question 6

Define gel electrophoresis

Answer 6

A technique used to separate DNA fragments on a piece of gel based on their sizes.