DNA replication

Question 1

Define DNA replication

Answer 1

• DNA replication is the process by which the genome’s DNA is copied in cells. this is crucial for biological inheritance

Question 2

Differentiate leading and lagging strand, including its configuration

Answer 2

• on the leading strand, DNA polymerase is moving towards the replication fork continuously
  ( 5 primer - 3 primer )
• on the lagging strand, DNA polymerase is moving away from the replication fork (discontinuous)
  (3 primer - 5 primer)

Question 3

ENZYME FUNCTIONS: what is the role of:
- helicase
- nuclease
- ligase
- primase

Answer 3

Ligase - joins okazaki fragments together to form continuous strands

Helicase - separates double stranded dna by breaking down hydrogen bonds

Primase - generates short primers on each of the template strands

nuclease - proof reads strands

Question 4

In which phase does DNA replication occur?

Answer 4

synthesis phase

Question 5

List the stages of DNA replication in logical order

Answer 5

1. initiation
2. elongation
3. termination

Question 6

describe the process of initiation in DNA replication

Answer 6

Initiation is the first process of DNA replication where an enzyme called helicase, unwinds the dna. This separates the complementary strands by breaking down hydrogen bonds between bases, forming a replication fork.

Question 7

describe the process of elongation in DNA replication

Answer 7

Leading strand
1. dna primers bind to the end of the strand, signalling the starting point of replication.

2. Dna polymerase then adds nucleotide segments towards the replication fork, forming a strand.
3. Then an enzyme called ligase will seal the fragments of newly formed DNA together, by forming phosphodiester bonds between DNA monomers.

Lagging strand
1. rna primase lays down rna primers.

2. Dna polymerase then adds free floating nucleotides in okazaki fragments to complementary to the original DNA strand
3. Dna polymerase I then removes rna primers and replaces it with dna
4. ligase seals the okazaki fragments together.

Question 8

describe the process of termination in DNA replication

Answer 8

1. nuclease proofreads the strands by removing the incorrectly incorporated nucleotides from the primer
2. Complementary strands recoil back into the double helix structure.

Question 9

How does DNA replication ensure the continuity of species?

Answer 9

In DNA replication, each daughter cell gets an equal amount of DNA. The process of DNA replication helps in the inheritance process by transfer of the genetic material from one generation to another.

from this, mutations can encode for advantageous traits which increases survival and genetic variation.

through sexual reproduction, this ensures the continuity of species as traits are passed on and becomes prevalent in the population.