1. Mutation

2. Bellwork
Explain the role of mRNA, tRNA, and rRNA in translation.

3. Objectives Define mutation
Explain the difference between base substitution and frameshift mutation
Explain how mutations affect living things

4. Key Terminology Mutation Base substitution Point mutation
Frameshift mutation

5. Definition Any change in the nucleotide sequence of DNA
Can result from
Single base change
Large regions of the chromosome change

6. Mutations within a gene fall into two general categories
First category-
Base substitution – replacement of one nucleotide with another
aka point mutation
Ex. Normal gene
AUG AAG UUU GGC GCA
Met Lys Phe Gly Ala
Mutated Gene
AUG AAG UUU AGC GCA
Met Lys Phe Ser Ala

7. Second Category Frameshift mutation
adding or deleting a base can alter the reading frame (triplet groupings)
the codons downstream from insertion/deletion will be regrouped into different codons
Ex: Normal Gene
AUG AAG UUU GGC GCA
Met Lys Phe Gly Ala
Base Deletion
AUG AAG UUG GCG CAU
Met Lys Leu Ala His

8. PROPERTY OF PIMA COUNTY JTED, 2010
Think-Pair-Share
Explain the difference between base substitution and frameshift mutation?
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class
PROPERTY OF PIMA COUNTY JTED, 2010 3

9. Mutagenesis Process by which mutants are created Can occur in two ways
Spontaneous mutation
result from errors during DNA replication or recombination
Exposure to a physical or chemical mutagen
Physical
exposure to x-rays and/or ultraviolet light
Chemical
Chemicals that interfere with correct DNA replication
They insert themselves and distort the double helix causing errors

10. Effect of Mutations No effect Harmful Beneficial
mutations can be neutral
have little or no effect on protein structure or function
Harmful
mutations that produce defective proteins that disrupt normal biological activity
Beneficial
alter protein structure or function that enables to adapt better to their environment

11. PROPERTY OF PIMA COUNTY JTED, 2010
Think-Pair-Share
“Mutation is the driving force of evolution”. Explain that statement
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class
PROPERTY OF PIMA COUNTY JTED, 2010 3

12. PROPERTY OF PIMA COUNTY JTED, 2010
20 Word Summary 48 37 18 21 14 13 23
In 20 words or less, summarize the most important aspects from today's lesson.
Word Summary
in 12 words or less, summarize the most important aspects from today's lesson
teacher uses a strategy to check all
PROPERTY OF PIMA COUNTY JTED, 2010 12