The DNA Code How does DNA affect living things? What happens when a mistake occurs in DNA?

DNA Chromosomes found in the nucleus of the cell are made of DNA DNA is a long strand of genetic material Made of the bases Adenine (A), Thymine (T), Cytosine (C) and Guanine (G) These bases encode instructions that allow your body to function

The DNA Code Parts of your DNA are genes that carry instructions for making the proteins that help build an organism The bases are divided into 3 letter codons that code for the 20 amino acids that build proteins After the protein is built in the cell, it is released to do its job

What happens if a mistake occurs? A mutation is a mistake that occurs in the sequence of DNA Mutations cause proteins to form incorrectly or not at all, causing a disruption in the cell’s function

Types of Mutations Substitution: exchanges one base for another Ex: DNA that reads ATCG now reads AACG Insertion: extra bases are inserted into a new place in the DNA Ex: DNA that reads ATCG now reads ATTCG Deletion: a piece of DNA is erased completely Ex: DNA that reads ATCG now reads AT

How do Mutations Affect an Organism? Mutations can be helpful, harmful or cause no effect to an organism Helpful Mutations are beneficial People with only one copy of the sickle-cell anemia gene are resistant to malaria

How do Mutations Affect an Organism? Harmful Mutations cause problems/disease Cancer usually results from a series of mutations within a single cell

How do Mutations Affect an Organism? Neutral Mutations cause no effect on the organism Red Hair is a mutation in humans that does not affect the person’s ability to survive and reproduce

Homework Draw a representation of DNA. Identify the bases and codons. What does a codon code for? What would happen if a codon was changed? List and describe three different types of mutations.