MUTATIONS MUTATIONS The alteration of an organisms DNA

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MUTATIONS

MUTATIONS

MUTATIONS • The alteration of an organism’s DNA • Wide range of mutations •

MUTATIONS • The alteration of an organism’s DNA • Wide range of mutations • Most mutations are automatically repaired by the organism’s enzymes… • …therefore they have no effect.

MUTATIONS • However…when the mutation is NOT repaired… • The resulting altered chromosome/gene structure

MUTATIONS • However…when the mutation is NOT repaired… • The resulting altered chromosome/gene structure is passed to ALL subsequent daughter cells of the mutant cell… • Mutations can be good or bad.

When are mutations inherited? • Mutations that occur in regular body cells (somatic cells)

When are mutations inherited? • Mutations that occur in regular body cells (somatic cells) will affect all daughter cells, but will not be passed to offspring • Can contribute to aging process • May lead to cancer…

When are mutations inherited? For example: • Mutation in lung cell will lead to

When are mutations inherited? For example: • Mutation in lung cell will lead to cancer, but cancer isn’t passed on to offspring

When are mutations inherited? • Mutations will only be passed on to offspring if

When are mutations inherited? • Mutations will only be passed on to offspring if they occur in the gamete (sex cells) • Results in genetic disorders

When are mutations inherited? • Lethal mutations result in the death of the organism

When are mutations inherited? • Lethal mutations result in the death of the organism • Often miscarriage

What causes mutations? • Malfunction during the process of meiosis • Exposure to a

What causes mutations? • Malfunction during the process of meiosis • Exposure to a physical or chemical agent • Called a mutagen • Examples: x-rays, chemicals (asbestos, formaldahyde), UV rays,

Two Types 1. GENE MUTATIONS— • changes in a single gene (a segment of

Two Types 1. GENE MUTATIONS— • changes in a single gene (a segment of DNA) 2. CHROMOSOMAL MUTATIONS— • changes in whole chromosomes (chromosome number or chromosome itself)

1. GENE MUTATIONS a. POINT MUTATION (Substitution) • Single nucleotide is substituted for the

1. GENE MUTATIONS a. POINT MUTATION (Substitution) • Single nucleotide is substituted for the wrong one • Ex: A-G instead of A-T • This can lead to…

1. GENE MUTATIONS 1) Silent mutation: has NO effect since some amino acids have

1. GENE MUTATIONS 1) Silent mutation: has NO effect since some amino acids have multiple sequences Ex: CUC codes for leucine CUA also codes for leucine

1. GENE MUTATIONS 2) Missense mutation: causes the wrong amino acid to be in

1. GENE MUTATIONS 2) Missense mutation: causes the wrong amino acid to be in sequence Ex: CUU codes for leucine CCU codes for proline

1. GENE MUTATIONS 3) Nonsense mutation: causes an early STOP codon Ex: UCA codes

1. GENE MUTATIONS 3) Nonsense mutation: causes an early STOP codon Ex: UCA codes for serine UGA codes for STOP

POINT MUTATION— SUBSTITUTION THE FAT CAT ATE THE RAT THE FAT CAT ATE THE

POINT MUTATION— SUBSTITUTION THE FAT CAT ATE THE RAT THE FAT CAT ATE THE HAT

1. GENE MUTATIONS b. FRAMESHIFT MUTATION • insertion or deletion of one or more

1. GENE MUTATIONS b. FRAMESHIFT MUTATION • insertion or deletion of one or more nucleotides • All codons are shifted • May cause serious effects • Such mutations can alter a protein so that it is unable to perform its normal functions.

FRAMESHIFT MUTATION— DELETION THE FAT CAT ATE THE RAT X FAT CAT ATE THE

FRAMESHIFT MUTATION— DELETION THE FAT CAT ATE THE RAT X FAT CAT ATE THE RAT THE TEF ATC ATA TET HER AT

FRAMESHIFT MUTATION— INSERTION THE FAT CAT ATE THE RAT THE FLA TCA TAT ETH

FRAMESHIFT MUTATION— INSERTION THE FAT CAT ATE THE RAT THE FLA TCA TAT ETH ERA T

Disorders caused by GENE MUTATIONS • • • Sickle-cell disease Tay-Sachs disease Huntington’s disease

Disorders caused by GENE MUTATIONS • • • Sickle-cell disease Tay-Sachs disease Huntington’s disease Cystic Fibrosis Albinism

2. CHROMOSOMAL MUTATIONS a. DELETION • Involves loss of a part or whole chromosome

2. CHROMOSOMAL MUTATIONS a. DELETION • Involves loss of a part or whole chromosome

A B C A C DELETION D E F

A B C A C DELETION D E F

2. CHROMOSOMAL MUTATIONS b. DUPLICATION • Opposite of deletion • A segment of the

2. CHROMOSOMAL MUTATIONS b. DUPLICATION • Opposite of deletion • A segment of the chromosome is repeated

A B B C A B C DUPLICATION D E F

A B B C A B C DUPLICATION D E F

2. CHROMOSOMAL MUTATIONS c. INVERSION • Direction of genes is reversed within chromosome (part

2. CHROMOSOMAL MUTATIONS c. INVERSION • Direction of genes is reversed within chromosome (part is upside-down)

A B C A E D INVERSION D E F C B F

A B C A E D INVERSION D E F C B F

2. CHROMOSOMAL MUTATIONS d. TRANSLOCATION • When part of a chromosome breaks off and

2. CHROMOSOMAL MUTATIONS d. TRANSLOCATION • When part of a chromosome breaks off and relocates to another part (non-homologous)

A B C G H D E F I J K L A B

A B C G H D E F I J K L A B C TRANSLOCATION J K L G H I D E F

2. CHROMOSOMAL MUTATIONS e. NONDISJUNCTION • Results in too few or too many chromosomes

2. CHROMOSOMAL MUTATIONS e. NONDISJUNCTION • Results in too few or too many chromosomes in a cell…

NONDISJUNCTION • MONOSOMY • Having only ONE copy of a chromosome instead of TWO

NONDISJUNCTION • MONOSOMY • Having only ONE copy of a chromosome instead of TWO • EX: Turner’s syndrome (has only one X chromosome)

NONDISJUNCTION • TRISOMY • Having THREE copies of a chromosome instead of TWO •

NONDISJUNCTION • TRISOMY • Having THREE copies of a chromosome instead of TWO • EX: Down Syndrome (3 copies of chromosome #21, trisomy 21)

NONDISJUNCTION

NONDISJUNCTION

Disorders caused by CHROMOSOMAL MUTATIONS • NONDISJUNCTION of Sex Chromosomes: • Klinefelter’s syndrome (male)

Disorders caused by CHROMOSOMAL MUTATIONS • NONDISJUNCTION of Sex Chromosomes: • Klinefelter’s syndrome (male) • Turner’s syndrome (female) • NONDISJUNCTION of Autosomal Chromosomes: • Down Syndrome (Trisomy 21)

Where can mutations occur? Somatic Cells (Body Cells) Germ Cells (Sex Cells)

Where can mutations occur? Somatic Cells (Body Cells) Germ Cells (Sex Cells)

Somatic Cells (Body Cells) • During or before mitosis • All new cells will

Somatic Cells (Body Cells) • During or before mitosis • All new cells will also be altered • The change is permanent • Only effects organism, not offspring

Germ Cells (Sex Cells) • Changes can occur in egg/sperm before, during or after

Germ Cells (Sex Cells) • Changes can occur in egg/sperm before, during or after meiosis • Altered egg/sperm may be fertilized —passing change to offspring • Changes may or may not be harmful • Harmful changes cause birth defects

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Mutations Mutations overview Smallscale mutations Missense mutations NonsenseMutations Mutations overview Smallscale mutations Missense mutations Nonsense
Mutations Mutations Types of Mutations Point Mutations occursMutations Mutations Types of Mutations Point Mutations occurs
Mutations in DNA Mutations Mutations changes in theMutations in DNA Mutations Mutations changes in the
MUTATIONS Mutations Changes to DNA are called mutationsMUTATIONS Mutations Changes to DNA are called mutations
GENE Mutations CHROMOSOMAL Mutations DNA Mutations A thirdGENE Mutations CHROMOSOMAL Mutations DNA Mutations A third
DNA MUTATIONS Advanced Biology MUTATIONS Genetic mutations occurDNA MUTATIONS Advanced Biology MUTATIONS Genetic mutations occur
Mutations Any change in an organisms DNA MutationsMutations Any change in an organisms DNA Mutations
DNA DNA RNA DNA RNA DNA RNA DNADNA DNA RNA DNA RNA DNA RNA DNA
DNA DNA cloning DNA Recombinant DNA Libraries DNADNA DNA cloning DNA Recombinant DNA Libraries DNA
DNA Shuffling DNA DNA Shuffling DNA DNA 1994StemmerDNADNA Shuffling DNA DNA Shuffling DNA DNA 1994StemmerDNA
Aqueous Alteration on Mars Importance Some background AlterationAqueous Alteration on Mars Importance Some background Alteration
Memorandum of Association Alteration of Memorandum Alteration OfMemorandum of Association Alteration of Memorandum Alteration Of
DNA and Mutations DNA Molecule Makeup Human DNADNA and Mutations DNA Molecule Makeup Human DNA
Mutations 1 Base Mutations 2 Chromosomal Mutations WhatMutations 1 Base Mutations 2 Chromosomal Mutations What
Mutations AP Biology Mutations n Point mutations singleMutations AP Biology Mutations n Point mutations single
Mutations 1 Base Mutations 2 Chromosomal Mutations WhatMutations 1 Base Mutations 2 Chromosomal Mutations What
GENETIC MUTATIONS Exploring point mutations and chromosomal mutationsGENETIC MUTATIONS Exploring point mutations and chromosomal mutations
Mutations Mutations Hollywoods images of mutation Mutations ActualMutations Mutations Hollywoods images of mutation Mutations Actual
Mutations and Genetic Engineering Mutations Types of mutationsMutations and Genetic Engineering Mutations Types of mutations
Types of mutations Point mutations Conditional mutations PointTypes of mutations Point mutations Conditional mutations Point
MUTATIONS WHAT ARE MUTATIONS KEY CONCEPT Mutations areMUTATIONS WHAT ARE MUTATIONS KEY CONCEPT Mutations are
Mutations Hollywoods images of mutation Mutations Actual MutationsMutations Hollywoods images of mutation Mutations Actual Mutations
NOTES 13 3 MUTATIONS 1 MUTATIONS MUTATIONS changesNOTES 13 3 MUTATIONS 1 MUTATIONS MUTATIONS changes