How Does DNA Divide?
DNA doesn't divide in the same way that a cell divides. Instead, DNA replicates itself before cell division. This replication process creates two identical copies of the DNA molecule, ensuring each daughter cell receives a complete set of genetic information.
The process of DNA replication can be broken down into these key steps:
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Unwinding and Unzipping: The double helix structure of the DNA molecule unwinds, and the two strands separate. This is achieved by the enzyme helicase, which breaks the hydrogen bonds between the base pairs holding the strands together. This separation creates a Y-shape called the replication fork. (Source: The first step is to unwind the double helix structure of the DNA molecule, and 'unzip' the strands. This is carried out by an enzyme called helicase, which breaks the hydrogen bonds holding the base pairs of the 2 strands together. Separating the strands creates a 'Y' shape called a 'replication fork'.)
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Priming: A short piece of RNA called a primer binds to the separated DNA strands. This primer provides a starting point for the DNA polymerase enzyme. (Source: To replicate the leading strand, a short piece of RNA called a primer (produced by an enzyme called primase) binds to...)
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Elongation (DNA Synthesis): The enzyme DNA polymerase adds nucleotides to the primer, building a new DNA strand complementary to each of the original strands. This process is known as elongation. (Source: DNA replication (known as elongation))
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Termination: The replication process stops when the entire DNA molecule has been replicated.
This entire process ensures that each new cell receives a complete and accurate copy of the genetic material. (Source: DNA replication is the process by which the genome's DNA is copied in cells. Before a cell divides, it must first copy (or replicate) its entire genome.)
Types of Cell Division: Where DNA Replication Plays a Crucial Role
The replicated DNA is then distributed to daughter cells through cell division. There are two main types:
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Mitosis: This is the process of cell division that produces two identical daughter cells from a single parent cell. Mitosis is essential for growth and repair in multicellular organisms. (Source: In particular, eukaryotic cells divide using the processes of mitosis and meiosis. Mitosis is common to all eukaryotes; during this process, a parent cell...)
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Meiosis: This type of cell division produces four genetically diverse daughter cells (gametes) from a single parent cell. Meiosis is crucial for sexual reproduction.
In both mitosis and meiosis, accurate DNA replication is essential to ensure the correct number of chromosomes and genetic information is passed on to each daughter cell. Errors during DNA replication can lead to mutations and potentially diseases like cancer. (Source: Each time a cell divides, it must first duplicate its genetic material in a process called DNA replication. Because defects in this process can cause...)
