(c)+DNA+replication

**__DNA REPLICATION __**
DNA replication is a process which occurs in ** living organisms ** to duplicate DNA so that an organism may pass on ** genetic characteristics ** to its offspring. This is the basis for genetic inheritance and must occur before cell division so that each cell contains the full set of genetic material.
 * DNA replication: **


 * Process of DNA replication:**

The two chains of the DNA section **separate** because of the hydrogen bonds that seperate. Each strand acts as a **template**, which means that they are used for creating another strand by using **nucleotides**. When the separation has occured, there are now two strands. These are both identical to one another and identical to the original DNA section. The DNA has effectively been replicated.

Errors that may occur:

If the DNA is not replicated before cell division then genetic mutations that can occur with increasing frequency as people age. For example, when DNA is exposed to sunlight, skin cancer as a mutation can occur. These mutations are not passed on to offspring. On the other hand, germline mutations occur in the reproductive cells and can cause hereditary diseases such as cystic fibrosis and Parkinson's disease. Down syndrome is also caused by genetic mutation. When an error occurs in the DNA replication or cell division and the cell gets extra genetic material from chromosome 21 it can result in the abnormalities see in Down syndrome.


 * Di****agram showing the steps of DNA replication:**

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 * Video demonstrating DNA Replication:**

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DNA Replication Vocabulary

DNA replication

This is the process where one DNA molecule becomes two DNA molecules. Transcription

This is the process whereby DNA is used to make RNA. Translation

This is the process whereby RNA is converted into protein. Nucleotides

These are the subunits that makeup DNA or RNA. Pyrimidines

This is the name of a class of base that might be found in DNA or RNA. This base has only one ring. Thymine (T), cytosine (C) and uracil (U) are examples. Purines

This is the name of a class of base that might be found in DNA or RNA. This base has two rings. Adenine (A) and guanine (G) are examples. Ribonucleic acid

This is the sugar that is found in RNA. Deoxyribonucleic acid

This is the sugar that is found in DNA. Hydrogen bonds

This is the type of bond that holds together the two strands of DNA. Helicase

This is the enzyme that separates or unwinds the two strands of DNA. DNA polymerase

This enzyme adds new DNA nucleotides to the growing DNA strand. It only adds bases in the 5’ to 3’ direction. That means it adds bases to the 3’ end. Leading strand

This is the strand of DNA that is replicated continuously. Bases are added in the 5’ to 3’ direction by DNA polymerase. Lagging strand

This is the strand of DNA that is replicated continuously. Bases are added in the 5’ to 3’ direction by DNA polymerase but small pieces of DNA must be tied together.

__WORKS CITED__

 * "11.2 DNA, Proteins and the Characteristics of Organisms." //Complete Biology//. Web.
 * //DNA Replication Process//. //YouTube.com//. Web. [].
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 * //DNA Replication. Lew-Port's Biology Place. Web.// <[]>
 * "Quizlet." //DNA Replication Vocabulary Flashcards//. Web. 03 Mar. 2012. .