What is the process by which DNA is copied before cell division?

DNA replication is the process by which a cell makes an identical copy of its DNA before it undergoes cell division. This is a critical step, as each daughter cell needs to receive an exact copy of the genetic material to ensure proper function and continuity of genetic information.

During DNA replication, the double helix structure of the DNA unwinds, and each strand serves as a template for the synthesis of a new complementary strand. The enzyme DNA polymerase plays a key role in adding nucleotides to form the new strands in accordance with the base-pairing rules.

In contrast, transcription refers to the process of synthesizing RNA from a DNA template, which is crucial for gene expression but not for copying the entire genome. Translation, on the other hand, is the process by which ribosomes synthesize proteins based on the sequence of mRNA, which follows transcription but does not involve DNA copying. Mutation denotes a change in the DNA sequence, which can occur randomly or due to environmental factors, but is not a systematic copying process.

Understanding DNA replication is essential as it underlies genetic inheritance and is fundamental to cell biology, impacting fields from genetics to medicine.