MUTATIONS

Read pages 296-301.Questions are not in order 

Define Mutation:

Give causes of mutations:Give environmental causes of mutations:

A.A.

B.B.

C.C.

D.D.

Anything that causes a mutation is called a ______

Use your glossary to define the next two terms.

Define Gene:

Define Chromosome:

Compare/contrast mutations in genes with mutations in chromosomes.

Compare/contrast mutations in reproductive cells with those in body cells.

Relate mutations to cancer.

Are all mutations bad? Give an example of a good mutation and an example of a bad mutation.

Which mutations are most likely bad mutations: Gene or chromosome?Why?

PRACTICE…

REVIEW

Make the DNA complement: C A T G A C T T A A T G C G A

______

Transcribe the DNA segment into RNA:C A T G A C T T A A T G C G A

______

Translate the RNA strand above into an amino acid sequence (use table p. 292)

Now imagine there is one mistake in the RNA strand above so that when it gets to the ribosome, it reads: G U A C U G U A U U A C G C U

What would the amino acid sequence look like now?

Or perhaps a base got deleted in the RNA sequence and at the ribosome, it looks like this: G U C U G U A U U A C G C U _

What is the amino acid sequence?

Describe point mutations and describe how it affects the synthesis of proteins

Describe frame-shift mutations and describe how it affects the synthesis of proteins

LOOK AT THIS ILLUSTRATION:

THE DOG BIT THE CAT

Rewrite the sentence showing a…

POINT MUTATION:

FRAMESHIFT MUTATION:

Name: ______Date: ______Class _____

PROBLEMWhat Type of Mutation Results in

SOLVINGSickle Cell Anemia?
LAB 11.3 Making & Using Tables

A disorder called sickle-cell anemia results from a genetic change in the base sequence of DNA. Red blood cells in patients with sickle-cell anemia have molecules of hemoglobin that are not shaped properly. As a result of this change in protein shape, sickled blood cells clog capillaries and prevent normal flow of blood to body tissue, causing severe pain.

SOLVE THE PROBLEM:

The table below shows the sequence of bases in a short segment of the DNA that controls the order of amino acids in the protein hemoglobin.

DNA Base sequences
Normal hemoglobin / GGG CTT CTT TTT
Sickled hemoglobin / GGG CAT CTT TTT

ANALYSIS

  1. Use the amino acid table on p. 292 of your textbook (or the one on the back of “How Codons Work” to determine the amino acid sequence for each strand. You must first transcribe the DNA strand given in the table into the mRNA codons, then translate the mRNA codons into the amino acids.

NORMAL HEMOGLOBIN: ______

SICKLED HEMOGLOBIN: ______

  1. Does this genetic change illustrate a point mutation or a frameshift mutation? Explain your answer.
  1. Why is the correct sequence of DNA bases important to the production of proteins?
  1. Assume that the base sequence reads GGG CTT CTT AAA instead of the normal sequence for hemoglobin. Would this result in sickled hemoglobin? Explain.