Why Does DNA Need to Replicate Before Cells Divide

Why does DNA need to replicate before cells divide? DNA needs to replicate before cells divide in order to have the same amount of DNA in two daughter cells as the parent cell.

DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. On the other hand, cell division is a process of dividing the parent cell into two daughter cells. Therefore, the replication of DNA is important for the doubling of other cellular components before cell division. This allows the acquisition of the same amount of cell content for each daughter cell.  

Key Areas Covered

1. What is DNA Replication
    – Definition, Features, Importance
2. What is Cell Division
    – Definition, Features, Importance
2. Why Does DNA Need to Replicate Before Cells Divide
    – Explanation

Key Terms

DNA Replication, Cell DivisionWhy Does DNA Need to Replicate Before Cells Divide

What is DNA replication

DNA replication refers to the process of producing an identical copy of a double-stranded DNA molecule. Each strand of the double-stranded DNA molecule serves as a template for the synthesis of the new DNA molecule. Therefore, the double-stranded DNA molecule should be unwounded prior to undergoing the replication. DNA replication occurs in a semi-conservative manner – each newly-synthesized, double-stranded DNA molecule contains an old DNA molecule.

DNA Need to Replicate Before Cells Divide

Figure 1: DNA Replication

Several enzymes, such as helicase, RNA primase, and DNA polymerase, are involved in DNA replication. DNA is unwound by helicase, producing the replication fork. RNA primase adds primers to the DNA template. Since DNA polymerase adds complementary base pairs to the template strand, the recruitment of DNA polymerase through the DNA template produces a complementary DNA strand. The newly synthesized strand is complementarily base-paired with the old strand.

What is Cell Division

Cell division is the process of splitting the parent cell into two or more daughter cells. According to modern cell theory, new cells derive from the existing cells. Thus, cell division is the mechanism of producing new cells from those existing cells. The two steps of cell division are nuclear division and cytokinesis. During nuclear division, the parent nucleus splits into two daughter nuclei while, during cytokinesis, the cytoplasm of the parent cell splits in between the two daughter nuclei, separating the parent cell into two daughter cells completely.

Why Does DNA Need to Replicate Before Cells Divide

Figure 2: Cell Division

The two main types of cell division are vegetative cell division, which occurs through mitosis, and the cell division responsible for the formation of gametes, the meiosis. Vegetative cell division is important for the growth, repair, and propagation by means of asexual reproduction. On the other hand, gametes are responsible for sexual reproduction. Sexual reproduction produces genetic variation through the random distribution of chromosomes, crossing over between homologous chromosomes, and fusion of male and female gametes.

Why Does DNA Need to Replicate Before Cells Divide

DNA replication is the process of replicating the double-stranded DNA molecules into two identical DNA molecules. On the other hand, cell division is a process by which a parent cell divides into two daughter cells. Therefore, before the cell divides, all the cellular components have to get doubled in order to produce two daughter cells with similar content to the parent cell. DNA replication is an essential process by which the cellular DNA content gets doubled. This allows the increase of DNA molecules in the cell twice. This DNA can then be divided into two daughter cells during the nuclear division phase of cell division. After that, the division of cytoplasm occurs between the two forming a new nucleus.     


Cell division is a process by which the parent cell divides into two. Here, each daughter cell should contain the same amount of cellular content. These include the cytoplasm, nucleus, and other cellular components. The process by which the nucleus gets doubled is DNA replication. Therefore, the DNA in the cell undergoes replication in order to produce double amounts of DNA. This allows the formation of two nuclei inside the parent cell during nuclear division. DNA replication provides the same amount of DNA to the daughter cells as the parent cell. Therefore, during DNA replication, a doubled amount of DNA is produced.


1. “Replication.” Nature news. Nature Publishing Group

Image Courtesy:
  1. Eukaryotic DNA replication” By LadyofHats – Own work (CC0) via Commons Wikimedia
  2. Three cell growth types” By domdomegg – Own Work (CC BY-SA 4.0) via Commons Wikimedia

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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