Transcript Mutations

Mutations
Chapter 11, Section 6
What are Mutations?
MUTATIONS are changes in the nucleotide
sequence of DNA that are INHERITABLE.
 Changes can effect a single gene (GENE
MUTATION)
 Changes can effect the number or
structure of the chromosome
(CHROMOSOMAL MUTATION)
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GENE MUTATIONS
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POINT MUTATIONS
Result of one nucleotide being
substituted for another
nucleotide in a DNA sequence
Can change amino acid
FRAMESHIFT MUTATIONS
Result of a nucleotide being
deleted or inserted into the DNA
sequence
Will change the remaining
sequence of amino acids
Chromosomal Mutations
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Chromosomal mutations cause more variation than gene
mutations
Not all mutations are harmful!! Mutations are the
ultimate source of genetic diversity in the living world!
What Causes Mutations?
They can be random mistakes in the
replicating of DNA or chromosome
crossovers in meiosis
 Physical and chemical agents called
MUTAGENS can also cause mutations
EX: Physical = high energy radiation
Chemical = chemicals that cause
incorrect base-pairing
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Biotechnology and the
Frontiers of Genetics
Chapter 13
BIOTECHNOLOGY: Using Organisms to
Perform Practical Tasks for Humans
In the past…
 Breeders use selective breeding
techniques to pass on desired
characteristics
 Hybridization: offspring are a blend of
parents
 Inbreeding: offspring similar to parents
(higher rate of genetic defects)
Today…
Scientists manipulate the living world on a
molecular level to benefit human society
 Use Recombinant DNA Technology
(combines genes from different sources)
 The DNA “code of life” is read and
interpreted the same in all living things!!
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Polyploidy
Occurs when chromosomes fail to separate
during meiosis and an organism inherits an
entire extra set of chromosomes
3N = triploid
4N = tetraploid
 Benefits: Makes plants taller and stronger;
good for bananas and citrus fruits
 Risks: Fatal in animals
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Genetically Modified Organisms
(GMO’s)
An organism with one or more genes
acquired by artificial means
 A TRANSGENIC has DNA from another
species included
 Benefits: Insulin producing bacteria,
herbicide resistant crops, leaner meat, etc.
 Risks: Food allergies, other negative
health effects; introduced species or
“superweeds”
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Animal Cloning
Benefits: Faster mass production of
animals with desired characteristics;
Reproduction of a GM animal
 Risks: Loss of life; Ethical concerns,
expensive
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DNA Fingerprinting
Gel Electrophoresis is the technique used
to create DNA fingerprints
 Can compare DNA from multiple subjects
to solve a crime, determine paternity, etc.
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The Complexity of Genetic
Expression in Eukaryotes
From the time the egg is fertilized, gene
expression is regulated as the cell divides into a
multicellular embryo.
7 days after fertilization, a human embryo is
mostly a hollow ball and about 100 embryonic
stem cells. Adult bone marrow also contains
stem cells.
Stems cells have the potential to differentiate into
any type of cell, therefore the potential use in
the medical field is bountiful.
The ethics of embryonic stem cell use continues to
be debated.
Homeotic Genes
Genes that control the
direct development of
body parts in specific
locations
Research helps use
understand the
diversity and
relatedness of
organisms