Introduction to DNA Replication in a Snap! Unlock the full A-level Biology course at [ Ссылка ] created by Adam Tildesley, Biology expert at SnapRevise and graduate of Cambridge University.
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The key points covered of this video include:
1. The Importance of DNA Replication
2. DNA Replication in Eukaryotes and Prokaryotes
The Importance of DNA Replication
The function of DNA is to contain the genetic information needed for the development and functioning of an organism. Each cell therefore needs to contain a full set of DNA. During the lifetime of an organism, cells must divide for growth, reproduction and to replace old or damaged cells. When a cell divides into two cells, both daughter cells must also contain the full set of DNA. Therefore, all the DNA in a cell must first be replicated. DNA replication takes place during interphase in the cell cycle - this is the phase before the cell starts to divide.
DNA Replication in Eukaryotes and Prokaryotes
In eukaryotes, DNA is stored in long, linear molecules called chromosomes which are found in the nucleus. Before a cell divides, every chromosome in the cell must make an identical copy of itself. Eukaryotes also have circular DNA that is found in mitochondria and chloroplasts. This circular DNA must also be replicated. In prokaryotes, DNA is found as a long, circular loop of DNA with many smaller circular strands called plasmids. All these circular strands of DNA must be copied before the prokaryotic cell is able to divide.
Summary
DNA must be replicated so that DNA can be inherited from parent cells to daughter cells
In eukaryotes, chromosomes in the nucleus and circular DNA in mitochondria and chloroplasts must be replicated
In prokaryotes, circular DNA in the nucleoid region and plasmids must be replicated
