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Do Now

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Regents Review Day 09Genetics

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DNA Structure

• DNA contains all of the genetic information of an individual.

• Chromosomes are made of DNA. They contain genes and are found in the nucleus of the cell.

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DNA Structure

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DNA Structure• DNA is made of 4

different repeated nitrogenous bases (A, T, C, G) arranged in a double helix.

• To form the double helix of DNA, A and T bond together and C and G bond together.

• Using this base pair rule, DNA can unzip and make copies of itself (DNA replication).

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DNA Structure

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DNA Function and Mutations

• The information in the sequence (order) of the bases is used to form all of the proteins necessary for our traits and survival.

• Any change in the order of the bases is called a mutation. Mutations usually cause disease or death.

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DNA Function and Mutations

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Protein Synthesis• Codons are sets of 3

bases that code for amino acids.

• The order of the amino acids in a protein chain determine how it will fold to make its 3 dimensional shape.

• Protein shape determines protein function (what it does).

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Protein Synthesis

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Environment and Gene Expression

• All of the body cells in an individual have the same DNA, but only certain genes are expressed (turned on).

• Gene expression is affected by the environment (light, temperature, etc…)

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Environment and Gene Expression

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Homework #42

• R.B. p. 49-50, #1-9 (full answers only)