DNA replication and its significance Grade 12 Life Sciences Notes with Activities Questions and Answers ,DNA replication is the process by which a cell makes an identical copy of its DNA. This process occurs during the S phase of the cell cycle and is crucial for growth, repair, and reproduction. It ensures that each new cell receives a complete set of genetic instructions, preserving the continuity of life.
Notes
DNA replication takes place at interphase before mitosis or meiosis begins. DNA replication is the process during which a DNA molecule makes an exact copy (replica) of itself.
Steps of DNA replication:
- The double helix unwinds.
- Weak hydrogen bonds between nitrogenous bases break and two DNA strands unzip (separate).
- Each original DNA strand serves as a template on which its complement is built.
- Free nucleotides build a DNA strand onto each of the original two DNA strands by attaching to their complementary nitrogenous bases (A to T and C to G).
- This results in two identical DNA molecules. Each molecule consists of one original strand and one new strand.
Importance of DNA replication Grade 12
DNA replication is important because it:
- Doubles the genetic material so it can be shared between the resulting daughter cells during cell division.
- Results in the formation of identical daughter cells during mitosis.