Mutations and Genetic Modifications TEKS BIO 6C

Instructions---READ EVERYTHING Today, you will learn about MUTATIONS. Follow the powerpoint, watching any videos that may be presented, and fill in your notes as you go. Be sure to read each slide to ensure you are completing your notes correctly.

Engage: One Wrong Letter- You have seen this video before Engage: One Wrong Letter- You have seen this video before. You may choose to watch it again, or move on to the next slide.

Explore: What about Mistakes?? Mutation Any changes to the genetic material (DNA) of a cell

Mutations click the link above to watch the video before moving on How Mutations Happen click the link above to watch the video before moving on How can mutations occur? Simple replication errors in DNA Environmental Mutagens

Types of Mutations Point Mutations Variation in Chromosome Number Base Pair Substitutions Silent Missense – new protein (Amino Acid Substitutions) Base Pair Insertions and deletions Triplet Repeats Frameshift Mutations Variation in Chromosome Number Chromosome Abnormalities Deletions Translocations Duplications Inversions

Point Mutations- one base change in the DNA sequence

Potential Results of Point Mutation Observe what happens when the following Point Mutations Occur for each set: CCA=Lys  CCC=Lys GGA=Arg  GGU=Arg UCU=Stop  UCA=Stop Amino acid meaning is not altered for each set This demonstrates a Silent mutation

Potential Result of Point Mutation If the amino acid meaning is changed, cells could be altered Example: Sickle Cell Anemia Valine is replaced with Glutamic Acid

Point Mutations: Frame Shift Insertion or deletion of one or more bases into the sequence of the gene How many DNA nucleotides can a ribosome read at one time? three letters (called CODONS) code into 1 amino acid (“word”) adding or removing one letter changes each subsequent “word” These mutations can make the DNA meaningless shortened and functionless protein

ACTIVITY READ ALL DIRECTIONS ON THE NEXT SLIDE AFTER PICKING UP THE PAGE FROM THE FRONT READ ALL DIRECTIONS ON THE NEXT SLIDE BEFORE COMPLETING ACTIVITY READ ALL DIRECTIONS ON THE NEXT SLIDE BEFORE COMPLETING ACTIVITY

ACTIVITY: “Modeling Chromosomal Mutations” READ EVERYTHING before moving on First, read the directions on the “Modeling Chromosomal mutations” page and follow the directions about how to complete the “original chromosome.” Cut out the original chromosome and paste it to the top of your notes. Continue with the slideshow AFTER completing the directions on each slide Cut out the colored diagram AND question and glue BOTH near the corresponding slide. (either on the slide or below it)

Deletion Frame Shifts A deletion of one or more bases on a section of the chromosome. Color the “deletion” section on your “modeling chromosomal mutations” page, answer the question that follows, then cut and glue both onto your slide.

Base Pair Insertions (Triplet Repeats) Occurs when DNA is not copied correctly and a segment is repeated Ex) Huntington Disease—CAG Repeat

Variation in Chromosome Number Having any number of chromosomes that does not equal 23 pairs. Ex) Down Syndrome – 3 Chromosome 21’s

Chromosome Abnormalities -Translocations -Duplications -Inversions

Translocations When one piece of a chromosome breaks off and attaches to another chromosome Color the “translocation” section on your “modeling chromosomal mutations” page, answer the question that follows, then cut and glue both onto your slide.

Duplications Occurs during crossing over and one chromosome ends up with more genes than it received. Color the “duplication” section on your “modeling chromosomal mutations” page, answer the question that follows, then cut and glue both onto your slide.

Inversions A reversal in the order of a segment of a chromosome Color the “inversion” section on your “modeling chromosomal mutations” page, answer the question that follows, then cut and glue both onto your slide.

Elaboration 1 The next several slides will give you information concerning a particular mutation. Use the small blue papers to write your responses. LABEL EACH SECTION CLEARLY! You will be graded on your responses.

Types of Mutations--1 DNA Sentence - THE FAT CAT ATE THE WEE RAT Mutation - THE FAT HAT ATE THE WEE RAT If this was a DNA sequence, what would this type of mutation be called? Could this change cause the protein sequence to change? How? If this type of mutation occurred, what, if any, might be the possible consequence for the organism?

Types of Mutations--2 Original Sample Gene - THE FAT CAT ATE THE WEE RAT Mutation - THE FAT KAT ATE THE WEE RAT If this was a DNA sequence, what would this type of point mutation be called? Was the meaning of the gene sentence altered? If this type of mutation occurred, would there be any consequence for the organism? Yes/No. Why or why not?

Types of Mutations--3 Original Sample Gene - THE FAT CAT ATE THE WEE RAT Mutation - THE FAT CAA TET HEW EER AT If this was a DNA sequence, what would this type of mutation (chromosome abnormality) be called? Could this change cause the polypeptide sequence to change? Yes/No How?

Types of Mutations--4 Original Sample Gene - THE FAT CAT ATE THE WEE RAT Mutation - THE FAT ATE THE WEE RAT If this was a DNA sequence, what would this type of mutation be called? Could this change cause the polypeptide sequence to change? How?

Types of Mutations--5 Original Sample Gene - THE FAT CAT ATE THE WEE RAT Mutation - THE FAT CAT XLW ATE THE WEE RAT If this was a DNA sequence, what would this type of mutation be called? Could this change cause the polypeptide sequence to change? How?

Evaluation The next several slides will show different types of mutations you’ve learned. On the back of your sheet, write the type of mutation you think is represented in the picture.

What Type of Mutation?--6

What Type of Mutation?--7

What Type of Mutation?--8

What Type of Mutation?--9

What Type of Mutation?--10

Genetic Modification--Where can it lead?