MUTATIONS

Quick Review Different traits allow us to stand out as individuals. Differences and similarities are due to our genetic instructions or genes inherited from our parents and their interactions with our environment. Genes are made of DNA.

Review Continued DNA provides the instructions for making proteins that determine your traits. 99.9% of your DNA is identical to every other human. Only about 0.1% variation in DNA allows for ALL of the differences seen in humans.

DNA Review DNA is composed of four chemical structures called nucleotides bases that line up to make a chain. The sequence of these determine our genetic instructions: A = Adenine T = Thymine C = Cytosine G = Guanine

DNA Continued DNA molecules take the shape of a double-stranded helix. When cells divide, DNA is copied. A mutation is a change in the DNA of an organism.

Mutations Can be inherited or passed from the parent or parents to the offspring. Can be acquired by: exposure to radiation, chemicals or some viruses or… can result from a mistake that occurs when DNA is being copied

Types of Mutations

Mutations Gene Mutations - One tiny part of the gene has a mistake. Chromosome Mutations - There is a change in the number or structure of the entire chromosome. Genes or chromosomes may be missing, duplicated or the chromosome is in the wrong order or location.

Results of Mutations 95% of human DNA is non-coding so there is a very small chance that any changes or mutations will have a noticeable effect.

Neutral Mutations Neutral mutations do not hurt or help the organism. There is a slim chance the mutation will be noticeable. Eye color Birth marks

Helpful Mutations Mutations that do not hurt the organism and actually increase its ability to survive. Mutations that make an organism better in some way; stronger, faster, better camouflage, etc. Peppered Moths HIV Immunity

Harmful Mutations Mutations that change the organism in a negative way and make it less likely to survive. Cancers Some Albinism (Goats clip) Lethal mutation – results in the death of the organism.

Mutations Continued Some mutations can be both harmful and helpful. A carrier of Sickle Cell Anemia is resistant to Malaria. Some mutations can be either harmful or helpful depending on the environmental conditions. An animal with a mutation that causes thicker fur would suffer if the environment was warm, but that same animal would benefit if its environment was cold.

Types of Genetic Disorders

Genetics Disorders A disease that is caused by an abnormality in a person’s DNA. Sickle Cell Anemia – recessive disorder that produces abnormal red blood cells. Down Syndrome – disorder with an extra copy of chromosome 21 Cystic Fibrosis – recessive disorder on chromosome 7 Alzheimer’s Disease – Autosomal dominant Hemophilia – bleeding disorder that is x-linked recessive

Genetics leads to new hope Genetic testing Looks for genetic abnormalities to help with better treatment Gene therapy Treatment working directly with a person’s cells to correct or treat cancers and genetic disorders

The Environment and Lifestyle Choices The environment you live in can affect your genes Examples: Pollution, radiation, and smoke Your lifestyle choices can also affect your genes For example: If someone is obese and predisposed to cardiovascular disease then they have an increased chance of having heart disease Smoking can increase your chances of developing lung cancer.