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:

1. The double helix unwinds.
2. Weak hydrogen bonds between nitrogenous bases break and two DNA strands unzip (separate).
3. Each original DNA strand serves as a template on which its complement is built.
4. 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).
5. 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.

PDF Downloadable Notes on The structure of DNA and RNA

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