Embed Size (px)
Citation preview
State Standard
2D. Describe the relationships between changes in DNA and potential appearance of new traits
Mutations (12.4)
Molecular Genetics
Mutations A permanent change in the nucleotide
sequence of a cell’s DNA is called a mutation.
Types of mutations Insertion Deletion Substitution
12.4 Gene Regulation and Mutation
Chapter 12
Molecular Genetics
Causes of Mutation Mutations can either occur spontaneously
or be caused by mutagens.
Examples of Mutagens: chemicals, radiation, x-rays, gamma rays, ultraviolet light, tobacco, free radicals.
12.4 Gene Regulation and Mutation
Chapter 12
Mutagen – Any agent that can harm DNA, causing a mutation.
Molecular Genetics
Effects of Mutations
Genetic Disorders (ex – Sickle Cell disease, Cystic Fibrosis)
Changes in shape & functionality of proteins.
Dysfunctional protein synthesis. Cancer
12.4 Gene Regulation and Mutation
Chapter 12
AAG CCC ATA TTT CGA AGA TAG
AAG CCC ATA TTT CGA AGA TAG
AAG CCC ATA TTT CGA AGA TAG
Molecular Genetics
Types of Mutations Substitution – 1 nucleotide base is
replaced with another. Insertion – an extra nucleotide is inserted
in the DNA sequence. Deletion – 1 nucleotide base is left out of
the DNA sequence. Insertions & deletions cause frameshifts,
which throw off the whole DNA code for that section.
12.4 Gene Regulation and Mutation
Chapter 12
Molecular Genetics
12.4 Gene Regulation and Mutation
Chapter 12
Molecular Genetics
Body-cell v. Sex-cell Mutation
Somatic (body) cell mutations are not passed on to the next generation.
Mutations that occur in sex cells are passed on to the organism’s offspring and will be present in every cell of the offspring.
12.4 Gene Regulation and Mutation
Chapter 12
1. A2. B3. C4. D
FQ 12
0% 0%0%0%
Molecular GeneticsChapter 12
12.4 Formative Questions
What is an immediate result of a mutation in a gene?
A. cancer
B. genetic disorder
C. nonfunctional enzyme
D. amino acid deficiency
1. A2. B3. C4. D
FQ 13
0% 0%0%0%
Molecular GeneticsChapter 12
12.4 Formative Questions
Which is the most highly mutagenic?
A. chemicals in food
B. cigarette smoke
C. ultraviolet radiation
D. X rays
Explain the difference between body-cell and sex-cell mutation.
Molecular Genetics
Chapter Assessment Questions
Chapter 12
Answer: A mutagen in a body cell becomespart of the of the genetic sequence in that cell and in future daughter cells. The cell may die or simply not perform its normal function. These mutations are not passed on to the next generation. When mutations occur in sex cells, they will be present in every cell of the offspring.
CAQ 3
1. A2. B3. C4. D
STP 3
0% 0%0%0%
Molecular GeneticsChapter 12
Standardized Test Practice
What type of mutation results in this change in the DNA sequence?
A. deletion
B. frameshift
C. insertion
D. substitution
TTCAGG TTCTGG
1. A
2. B
STP 5
Molecular GeneticsChapter 12
Standardized Test Practice
0%0%
The structure of a protein can be altered dramatically by the exchange of a single amino acid for another.
A. TrueB. False
