DNA Replication
Definition:
DNA replication is the biological process in which a cell makes an exact copy of its DNA. It
occurs during the interphase of the cell cycle, before mitosis or meiosis, ensuring genetic
continuity.
Steps of DNA Replication:
1. Unwinding of DNA – The enzyme helicase unwinds the double helix, breaking the
hydrogen bonds between base pairs.
2. Strand Separation – The two DNA strands unzip, forming a replication fork.
3. Template Formation – Each original DNA strand serves as a template for the formation of
a new complementary strand.
4. Complementary Base Pairing – The enzyme DNA polymerase adds new nucleotides to
each template strand following the base-pairing rules:
Adenine (A) pairs with Thymine (T)
Cytosine (C) pairs with Guanine (G)
5. Formation of Two Identical DNA Molecules – The process results in two identical semi-
conservative DNA molecules (each containing one original and one newly synthesized
strand).
6. Proofreading and Error Correction – DNA polymerase checks for and corrects errors to
ensure the accuracy of replication
Importance of DNA Replication:
Ensures Genetic Continuity – Daughter cells receive identical genetic material.
Supports Growth and Development – Essential for cell division in multicellular organisms.
Aids in Tissue Repair – Helps replace damaged or dead cells.
Maintains Genetic Stability – Prevents mutations that could lead to genetic disorders.
Essential for Reproduction – Enables the transmission of genetic information to offspring.
Definition:
DNA replication is the biological process in which a cell makes an exact copy of its DNA. It
occurs during the interphase of the cell cycle, before mitosis or meiosis, ensuring genetic
continuity.
Steps of DNA Replication:
1. Unwinding of DNA – The enzyme helicase unwinds the double helix, breaking the
hydrogen bonds between base pairs.
2. Strand Separation – The two DNA strands unzip, forming a replication fork.
3. Template Formation – Each original DNA strand serves as a template for the formation of
a new complementary strand.
4. Complementary Base Pairing – The enzyme DNA polymerase adds new nucleotides to
each template strand following the base-pairing rules:
Adenine (A) pairs with Thymine (T)
Cytosine (C) pairs with Guanine (G)
5. Formation of Two Identical DNA Molecules – The process results in two identical semi-
conservative DNA molecules (each containing one original and one newly synthesized
strand).
6. Proofreading and Error Correction – DNA polymerase checks for and corrects errors to
ensure the accuracy of replication
Importance of DNA Replication:
Ensures Genetic Continuity – Daughter cells receive identical genetic material.
Supports Growth and Development – Essential for cell division in multicellular organisms.
Aids in Tissue Repair – Helps replace damaged or dead cells.
Maintains Genetic Stability – Prevents mutations that could lead to genetic disorders.
Essential for Reproduction – Enables the transmission of genetic information to offspring.
