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DNA: Replication and Mutation. RED => COPY INTO NOTEBOOK. What is DNA?. DNA = deoxyribonucleic acid DNA is the “blueprint” for the cell contains the instructions that tells the cell how to do things and what to make DNA is like blueprints for making a city, which in this case is the cell.
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RED => COPY INTO NOTEBOOK What is DNA? • DNA = deoxyribonucleic acid • DNA is the “blueprint” for the cell contains the instructions that tells the cell how to do things and what to make • DNA is like blueprints for making a city, which in this case is the cell Amoeba Cell
What is DNA made of? • DNA is made up of 4 bases: • Adenine (A), Thymine (T), Cytosine (C), Guanine (G) Rules for DNA Bases: 1. A pairs with T 2. G pairs with C “Chargaff’s Rules”
Structure of DNA • DNA is made up of two strands (double stranded) • Each strand has the bases connected to a PHOSPHATE BACKBONE • The two strands wrap around each other in a winding staircase manner (helix)
DNA Replication • In order for you to survive, your cells need to replicate themselves. In order for them to do that, they need to replicate their DNA • Every cell in your body has the same DNA, because every time one of your cells divides, it makes a copy of its DNA to give to the new daughter cells
How does DNA replicate? • The DNA is unzipped and the original strands are used to help make the new molecules – See Demonstration
What are mutations? • MUTATIONS are any changes in the sequence of bases of DNA • Mutations DO NOT lead to this • Mutations COULD lead to this Colon cancer cells
How do mutations occur? • Sometimes during replication, the cell makes a mistake and adds the wrong base • When the cell replicates its DNA again, the two strands that are produced are no longer exactly the same • This usually will cause the new cell to die, but sometimes it can cause the cell to divide when it is not supposed to cancer
Replication How do mutations occur?