BELL WORK:

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• Title: DNA Mutations• Page: 38• Date: 10-28-14• Essential Question: How can I identify changes in

DNA?• Yes, Cornell Notes!

Mutations: changes in genetic material•May be caused by:

o mistakes during replicationo mistakes during transcriptiono environmental factors (like radiation)

Point mutation: changes a single base • also called substitution• three types:

o silent: no change to the proteino missense: one wrong amino acido nonsense: early stop

Which type of point

mutation is this?

Types of Mutations

Frameshift mutation: affects the entire amino acid sequence• three types:

o insertion: an extra base is addedo deletion: a base is subtractedo duplication: an entire codon is repeated

Think-Pair-Share

Which is more likely to have a bigger effect on an organism, a point mutation or frameshift

mutation?

Why?

mutation

point

frameshift

protein

frameshift mutationpoint protein

Quickwrite

• Answer the following question in your journal:–If you have a mutation in a body cell (skin, stomach,

bone, etc.), can you pass that mutation on to your children? Why or why not?

Do you know of any diseases caused by genetic mutations?

Sickle Cell AnemiaThese are the sickle-shaped blood cells of someone with sickle cell anemia.Sickle cell anemia is the result of a point mutation, a change in just one nucleotide in the gene for hemoglobin. This mutation causes the hemoglobin in red blood cells to distort to a sickle shape when deoxygenated. The sickle-shaped blood cells clog in the capillaries, cutting off circulation.Having two copies of the mutated genes cause sickle cell anemia, but having just one copy does not, and can actually protect against malaria - an example of how mutations are sometimes beneficial.

Color Blindness

• Most forms are caused by a point mutation on the X chromosome.

What number do you see? A color blind person won’t see anything. A color deficient person may see the number 35

Achondroplasia

• This is the most common form of dwarfism. It is caused by a substitution mutation for the gene that codes for bone growth.