EOC Mutation review 2013 TEK 6E Concepts ProceduresApplication

Concepts 1.Can you think of 3 words that mean “take away”? 2.Can you think of 2 words that mean “replace”? 3.Can you think of 1 word that means “add to”?

MUTATIONS Random change in the sequence of nucleotides in DNA. Can be harmful, beneficial or have no effect. Two types: –Chromosomal –Gene

GENE MUTATIONS permanent change in a gene or chromosome n n Point Mutations - a change in a SINGLE BASE PAIR in DNA n n Possible results: a missense, nonsense or silent mutation. 1.What happened to the Guanine base? 2.Did this change the Amino Acid sequence?

a.Missense Point Mutations – point mutations that result in a single AMINO ACID change. The change in the nitrogen base changed the amino acid “Gly” to the amino acid “Ser”

b. Nonsense Point Mutations – point mutations that create a premature(early) translation stop signal: (or “stop codon”), causing the protein to be shortened The change in the nitrogen base caused protein synthesis to stop early.

c. Silent Point Mutations – point mutations that DO NOT cause amino acid changes within the protein. The change in the nitrogen base made no difference in the amino acid made. Any one of us could have silent mutations!

Frame Shift Mutations - a single nitrogen base is added to or deleted from a DNA strand causing all the nitrogen bases behind to shift forward or backward, thus creating NEW CODONS. ? This causes the sequence of amino acids on the strand to change resulting in a DIFFERENT PROTEIN.

CHROMOSOMAL MUTATIONS

TYPES OF Chromosomal MUTATIONS 1.DELETION 2.INVERSION 3.DUPLICATION 4.TRANS- LOCATION

Chromosomal MUTATIONS DRASTIC CHANGES IN A CHROMOSOME.

DELETION Part of chromosome is missing. What section of the chromosome is missing?

DUPLICATION part of a chromosome breaks off and is incorporated into its homologous chromosome. Chromosome 1a Chromosome 1b

TRANSLOCATION Part of or whole chromosome attaches to a 2nd ( non- homologous ) chromosome. #1 #2 #1 with some of #2 #2 with some #1

INVERSION Part of chromosome breaks-off and re-attaches upside-down. 1.Has this chromosome lost any nucleotides ( bases)? 2.Could the messenger RNA’s made from the mutated chromosome be affected knowing that RNA polymerase only works in one direction when it transcribes the DNA? 3.Ultimately, what would be built incorrectly during translation?

PROCEDURE- use the following slides to identify the procedural type errors some students may make during tests.

1. The diagrams above represent portions of the genes that code for wing structure in two organisms of the same species. Gene 1 was taken from the cells of a female with normal wings. Gene 2 was taken from the cells of a female with abnormal wings. The abnormal wing structure was most likely due to: a.an insertion c.a substitution b.a deletiond.normal replication

2. The assembly of a messenger RNA strand that normally begins with UAC has been changed so that the newly assembled messenger RNA strand begins with UAG. Which of the following will most likely occur? a.The protein will be missing the first amino acid. b.The mRNA will become attached to a ribosome. c.All of the amino acids that make up the protein will all be different. d.The production of the protein may be stopped.

3. The diagram below shows a normal gene sequence and three mutated sequences of a DNA segment. Which row in the chart below correctly identifies the cause of each type of mutation? a. Row 1 c.Row 3 b. Row 2 d.Row 4

4.

INSTRUCTIONS: Mutations: Please draw what the chromosome would look like after the mutation Each of the chromosomes will be represented like this “ACAGGT*CCT” The bolded and highlighted portion is where the mutation will occur.

APPLICATION Use the following slides to see if students can apply the content in new ways.

People who have been exposed to excessive radiation often experience mutations in their chromosomes. What conclusion can be made, if these mutations occur in the chromosomes of skin cells? A. They will pass on the mutation to their offspring. B. They will experience an increased risk of cancer. C. Their skin cells may turn into liver cells.

A deletion of a DNA base from a gene affects an organism by: a. causing future gametes to have additional chromosomes b. changing the sequence of amino acids in a protein c. causing chromosome fragments to form long chains

In May 2011, scientists announced the discovery of a link between the environment and genetics in triggering the onset of multiple sclerosis. Based on blood samples from 13,000 people, the scientists discovered an interaction between Vitamin D, obtained by exposure to sunlight or through food, and 4 genes. These 4 genes are responsible for making the proteins which regulate the onset and progression of the disease. Apparently, Vitamin D helps to repair damage to these genes, thus reducing the effects of the disease. After reading the above text, what might occur if someone does not have enough Vitamin D in their body? A. The genes produce less protein. B. The genes may become damaged. C. The genes may translocate to another chromosome.