DNA REPLICATION

Question 1

What is the process by which a DNA molecule makes an identical copy of itself?

Answer 1

DNA replication

Question 2

What is the name of the short RNA primer that initiates DNA synthesis?

Answer 2

Primase

Question 3

During DNA replication, which enzyme is responsible for joining the Okazaki fragments on the lagging strand?

Answer 3

DNA ligase

Question 4

What is the name of the process where the two strands of DNA separate during replication?

Answer 4

DNA unwinding

Question 5

What is the term for the Y-shaped structure that forms during DNA replication?

Answer 5

Replication fork

Question 6

What is DNA replication?

Answer 6

DNA replication is the process by which DNA makes a copy of itself during cell division.

Question 7

What is the function of DNA polymerase in DNA replication?

Answer 7

DNA polymerase is the enzyme responsible for synthesizing new DNA strands by adding nucleotides to the growing DNA chain.

Question 8

What is the function of primers in DNA replication?

Answer 8

providing a starting point for DNA polymerase.

Question 9

What is the leading strand in DNA replication?

Answer 9

The leading strand is the DNA strand that is synthesized continuously in the 5’ to 3’ direction.

Question 10

What is the lagging strand in DNA replication?

Answer 10

The lagging strand is the DNA strand that is synthesized discontinuously in the 5’ to 3’ direction, forming Okazaki fragments.

Question 11

What is the role of DNA ligase in DNA replication?

Answer 11

DNA ligase is the enzyme that joins Okazaki fragments together on the lagging strand, sealing any gaps in the DNA.

Question 12

What are the consequences of errors in DNA replication?

Answer 12

Errors in DNA replication can lead to mutations, genetic disorders, or cell death.

Question 13

What is a primer

Answer 13

A short strand of nucleotides which binds to the 3”end of the template dna strand allowing DNA polymerase to add dna nucleotides

Question 14

DNA is replicated Prior to what

Answer 14

Cell devision

Question 15

What does DNA polymerase need to start replication

Answer 15

Primers

Question 16

What are the requirements for DNA replication

Answer 16

Original DNA template
Free DNA Nucleotides
DNA polymerase
primers
Ligase

Question 17

Stage 1 of DNA replication

Answer 17

The dna is unwound and unzipped, hydrogen bonds between bases are broken to form two template strands.
This process occurs at several locations on a DNA molecule

Question 18

Stage 2 of DNA replication

Answer 18

1.DNA polymerase will add the free DNA Nucleotides using complementary base pairing to the 3” end of the new dna strand which is forming.
2 . The leading strand is synthesised continuously. DNA Polymerase adds nucleotides to the 3”ended strand in a 5”-3” direction.
3. The lagging strand is synthesised in fragments, As DNA Polymerase can only add dna nucleotides in a 5”- 3” direction. The fragments are then sealed together by the ligase enzyme

Question 19

Third stage of DNA REPLICATION

Answer 19

Two new strands twist to form a double helix, each is identical to the original strand.

Question 20

What is PCR

Answer 20

The amplification of DNA in vitro ( in glass )

Question 21

Requirements of PCR

Answer 21

DNA
Complementary primers
Thermal cycler
Heat tolerant polymerase
Nucleotides

Question 22

Process of PCR

Answer 22

1. DNA is heated to 92-98 degrees Celsius, to denature the DNA and separate the two strands
2. DNA is cooled between 50-65 degrees c to allow primers to bind to the target DNA Sequences
3. Complementary primers are added, which are complementary to the target sequences at the two ends of the region to be amplified
4. DNA heated to between 70-80 dc, tolerant dna polymerase added. Which replicates the region of DNA to be amplified. Two strand are formed
5. Repeated cycles of heating and cooling amplify the target region of DNA

Question 23

Practical applications of PCR

Answer 23

Solve crimes
Settle paternity suits
Diagnoses genetic disorders