Welcome to Genetic Mutations!Welcome to Genetic Mutations!

https://www.youtube.com/watch?v=6zMIl7x2WSY

Share out!Share out!

Today’s objective: SWBAT explain how genetic

mutations occurSWBAT distinguish between the 3

types of genetic mutations

GENETIC DISORDERS ARE CAUSED BY GENETIC MUTATIONS!!!!!!

A. Introduction to MutationsA. Introduction to Mutations

-A mutation is a change in DNA sequence (order of nucleotides).

-Mutations are important because they increase genetic variation.

Mutations in Body CellsMutations in Body Cells

-Mutations in body cells cannot be passed on to your children, however, they can cause cancer or other problems in your body. A cancer cell.

Cancer as a result of mutations in Cancer as a result of mutations in body cells:body cells:

A person with skin cancer-This is why it’s important to always wear sunscreen!

Cancer as a result of mutations in Cancer as a result of mutations in body cells:body cells:

Tongue cancer and lung cancer are often caused by changes in body cells as a result of smoking, so don’t smoke!!!

Mutations in Reproductive (Sex) Mutations in Reproductive (Sex) CellsCells

-Mutations in sex cells (sperm and egg cells) can lead to changes in the DNA sequence which can be passed down to a person’s children.

Mutations in sex cellsMutations in sex cells

-X-men and X-women would be a result of mutations in sex cells. These people inherited mutated (changed) DNA from their parents:

Good vs. Bad MutationsGood vs. Bad Mutations

Mutations can be good as well as bad. A good mutation could lead to a change in a protein that allows an animal to run faster or see better. A bad mutation could lead to a change in a protein that causes a genetic disease such as Sickle Cell Anemia or Hemophilia.

TURN AND TALKTURN AND TALK

WHAT IS A MUTATION?

WHAT IS THE MAIN DIFFERENCE BETWEEN MUTATIONS IN SEX CELLS AND MUTATIONS IN BODY CELLS?

B. Gene MutationsB. Gene Mutations

There are 3 main types of gene mutations:

1. POINT MUTATIONSSUBSTITUTIONS

2. SILENT MUTATIONS3. FRAMESHIFT

MUTATIONS INSERTIONSDELETIONS

1. Point mutation1. Point mutation

-Point mutation-a change in one base pair in a DNA sequence.

Example: AUG=Met AAG=Lys

-A point mutation can cause an amino acid to change, which will change the structure of the protein being made.

POINT MUTATIONPOINT MUTATION

Picture of A Point MutationPicture of A Point Mutation

Normal

Point mutation

mRNA

Protein Stop

Stop

mRNA

Protein

Replace G with A

Point mutations in our lives!Point mutations in our lives!

-Sickle cell anemia is a blood disease caused by a point mutation.

-A single nucleotide is changed from “A” to “T” which causes the amino acid to change from glutamic acid to valine:

Normal: ACT CCT GAG GAGAmino Acids: Thr – Pro – Glu – Glu Sickle cell: ACT CCT GTG GAGAmino acids:Thr – Pro – Val – Glu

Point mutations in our lives!Point mutations in our lives!

-People with sickle cell anemia often experience a lot of pain and swelling and have trouble exercising.

Sickle cells do not move smoothly

through blood vessels like normal cells do.

Sickle cells get stuck and cause blood clots.

Sickle cells also can’t carry Oxygen as effectively as normal

Cells.

2. SILENT MUTATION2. SILENT MUTATION

A TYPE OF MUTATION THAT RESULTS IN A CHANGE IN CODON BUT DOES NOT CHANGE THE AMINO ACID CREATED.

Codons can code for the same Amino Codons can code for the same Amino acid!acid!

Silent MutationsSilent Mutations

Single nucleotide mutation that does not result in a change in the amino acid sequence of the protein made

THINK PAIR SHARETHINK PAIR SHARE

WHAT IS THE DIFFERENCE BETWEEN A POINT MUTATION AND A SILENT

MUTATION?

-Frameshift mutation- Adding or deleting nucleotides to a DNA sequence.

-A frameshift mutation is much worse than a point mutation because it causes the entire DNA sequence to be shifted over!

Example: DNA: ATTAAACCG

ATAAACCG

3. Frameshift mutation3. Frameshift mutation

Delete this T

2 types of Frameshift mutations:2 types of Frameshift mutations:

INSERTION DELETION

FRAME-SHIFT MUTATIONS:FRAME-SHIFT MUTATIONS:

Insertion: Nucleotide added – Entire DNA sequence changed

Deletion: Nucleotide missing – Entire DNA sequence changed

V. Frameshift mutationV. Frameshift mutation

mRNAProtein

Frameshift mutation

Deletion of U

Frameshift MutationsFrameshift Mutations

Crohn’s Disease is caused by a frameshift mutation.

It causes inflammation to the digestive tract.

THINK PAIR SHARETHINK PAIR SHARE

WHAT IS THE DIFFERENCE BETWEEN A POINT MUTATION AND A FRAMESHIFT MUTATION?

Difference between a point mutation Difference between a point mutation and a frameshift mutation.and a frameshift mutation.

BRAIN POP VIDEOBRAIN POP VIDEO

https://www.youtube.com/watch?v=efstlgoynlk

GUIDED PRACTICE- GUIDED PRACTICE- WHITEBOARDSWHITEBOARDS

Is this a point mutation or a frameshift mutation?

-It’s a point mutation because only one nucleotide changed!

Questions:Questions:

THE DOG BIT THE CAT

THE DOG BIT THE CAR

Point or frameshift?

Point!

QuestionsQuestions

THE DOG BIT THE CAT

THE DOB ITT HEC AT

Point or frameshift?

-frameshift

GUIDED PRACTICEGUIDED PRACTICE

WHAT IS THE NAME OF THE TYPE OF MUTATION THAT RESULTS IN A

CHANGE IN CODON BUT DOES NOT CHANGE THE AMINO ACID?

SILENT MUTATIONSILENT MUTATION

A TYPE OF MUTATION THAT RESULTS IN A CHANGE IN CODON BUT DOES NOT CHANGE THE AMINO ACID CREATED.

GUIDED PRACTICEGUIDED PRACTICE

What type of frame-shift mutation is shown below?

AnswerAnswer

INSERTION- Frameshift

GUIDED PRACTICEGUIDED PRACTICE

What type of frame-shift mutation is shown below?

AnswerAnswer

DELETION- Frameshift

WHAT TYPE OF MUTATION IS SHOWN BELOW?

AnswerAnswer

POINT

BEFORE THE MUTATION, A DNA CODON CODES FOR THE AMINO ACID VALINE. AFTER THE MUTATION, THE DNA CODON STILL CODES FOR VALINE.

WHAT TYPE OF MUTATION IS THIS?

AnswerAnswer

SILENT

ObjectiveObjective

Today’s objective: SWBAT explain how genetic mutations

occur SWBAT distinguish between the 3 types of

genetic mutations

Rate 1-5 on how confident you feel with these objectives1- Poor5- Excellent