Set up Cornell Notes on pg. 11 Topic: 8.7 Mutations Essential Question: Explain why a frameshift mutation has a greater effect than do point mutations. 8.7 Mutations 2.1 Atoms, Ions, and Molecules Explain why a frameshift mutation has a greater effect than do point mutations. KEY CONCEPT Mutations are changes in DNA that may or may not affect phenotype

Points to Ponder P.10 Point Mutation Frameshift Mutation

Points to Ponder (Top of p. 10) What do you think of when you hear the word “mutation”? Are they always bad? Give me an example

Mutations?

Mutations (1m13s)

KEY CONCEPT Mutations are changes in DNA that may or may not affect phenotype.

Not all mutations are bad, but most do have negative effects What mutations do you notice here? Why might these be problematic?

A mutation is a change in an organism’s DNA. Many kinds of mutations can occur, especially during replication.

GENE MUTATIONS A point mutation substitutes one nucleotide for another. GAT CTC GAT CAC Draw a picture: middle of p. 10

Example of a point mutation Sickle cell anemia

THE CAT ATE THE RAT THC ATA TET HER AT…. 2) A frameshift mutation inserts or deletes a nucleotide in the DNA sequence. THE CAT ATE THE RAT THC ATA TET HER AT…. Draw a picture: bottom of p. 10

Example of a frame shift mutation: Tay–Sachs disease Develops @ around 6 months of age Nerves start deteriorating Child becomes blind, deaf, and unable to swallow Death usually occurs before the 4th year

Chromosomal mutations affect many genes may occur during crossing over

Mutations may or may not affect phenotype (looks). Chromosomal mutations tend to have a big effect. Some gene mutations change phenotype. Ex: down syndrome

Some gene mutations do not affect phenotype. A mutation may be silent. Ex: Cystic Fibrosis- caused by a deletion blockage no blockage

Mutations in body cells do not affect offspring. Ex: Lung cancer Skin cancer

Mutations in sex cells can be harmful or beneficial to offspring. Natural selection often removes mutant alleles from a population

CCR5 32 is a deletion thought to resist the bubonic and pneumonic plague as well as HIV Beneficial mutations Mutations that cause resistance to antibiotics

Conjoined Twins Chang and Eng Bunker Born in 1811 Married sisters Had 21 children between them In modern times, they could have easily been separated Died on the same day in 1874 Chang contracted Pneumonia and died in his sleep- Eng refused to be separated from his dead twin and died several hours later.

Mutations caused by Mutagens Radiation

Mutations 2 (5m37s)