Download Genetic Mutations & Genetic Engineering

Genetic Mutations &
Genetic Engineering
Ch. 12-4 (pgs. 307-308)
Ch. 13-2 thru 13-4 (pgs.
322-333)
12-4 Mutations

Mutations= Changes in genetic material
• 2 Types of mutations :
• Chromosomal and Gene

Gene Mutations= Changes to the
codons & genetic message
• Point Mutations: Caused by changes in one or
a few nucleotides
• EX:
substitutions, insertions or deletions
12-4 Mutations

Gene Mutations Cont…
•
Frameshift Mutations: Occur from insertions or
deletions because they shift the “reading frame” of
the genetic message.
• They never occur from substitutions

Chromosomal Mutations: Involve changes in
the # or structure of chromosomes:
• EX: Inversions, duplications, deletions & translocations
• Some neither help nor harm, some are beneficial for
genetic variation, some cause disorders and cancer
13-2 Manipulating DNA
Scientists have discovered how to use
their knowledge of DNA to study &
change DNA molecules
• EX: Extract DNA from cells, cut DNA into smaller
pieces, identify sequence of bases in DNA, make
unlimited copies of DNA
13-2 Manipulating DNA

Genetic Engineering: Making changes
in the DNA code of a living organism.
Occurs by:
• DNA Extraction: The cells are opened & DNA
•
is separated from other cell parts
Cutting DNA: Uses restrictions enzymes to
cut specific sequences of nucleotides creating
“sticky ends” that will match up with
complimentary bases
13-2 Manipulation DNA
Restriction enzyme cutting DNA between
Guanine & Adenine
13-2 Manipulation DNA

Separating DNA= Commonly done by
gel electrophoresis. Electric volts applied
to DNA cause negative DNA fragments
to move to positive ends of the gel
EX: 2 DNA samples showing identical bands of the
same size and thickness show: same amount
of DNA, fragments of the same size, the
same DNA molecules
• Locates specific genes, compares genetic
composition like paternity tests
13-2 Manipulation DNA


Knowing the sequence of an Organisms
DNA allows scientists to study specific
genes
Reading DNA Sequences= Enzymes trigger
DNA replication by adding nitrogenous bases
(A,T,G,C) to an unknown single-stranded DNA
template
•
•
•
Uses fluorescent dyes to label the different
nitrogenous bases & stop replication
Uses nucleotide bases to trigger & stop replication
Uses gel electrophoresis to show DNA bands
13-2 Manipulating DNA

Making Copies: Uses PCR (polymerase
chain reaction).
• Triggers DNA replication by using
•
complimentary “primers” added to singlestranded DNA molecule that scientist wants to
copy
DNA polymerase makes copies of the area
between the two primers
13-3 Cell Transformation
Transformation: A cell takes in DNA from outside the cell
Plasmid: Foreign DNA formed into a small circular DNA
molecule. Used to incorporate foreign DNA into bacteria
that will replicate allow it to be replicated
Genetic Marker: Gene that makes it possible to distinguish
bacteria that carry plasmids from those that don’t.
EX: Gene for antibiotic resistance is used to select for
bacteria that carry plasmids when that antibiotic is added
13-3 Cell Transformation

Transforming Plant Cells Can Occur 3
Ways:
• Use bacteria that are able to insert plasmids
•
•
into the plant
Remove plant cell walls so plasmid DNA is
taken in by the nucleus
Insert DNA directly into the cell
Cell Transformation

Transforming Animal Cells Can Occur
By:
• DNA injected directly into the nucleus
• Enzymes help injected DNA become
•
incorporated in the cell’s chromosomes
Foreign DNA contains genetic markers that to
determine which genes have been
transformed
13-4 Applications of Genetic
Engineering

Transgenic Organism: Organism that
contains genes from other species
• Scientists use Genetic Engineering to make
transgenic organisms
13-4 Applications of Genetic
Engineering


Transgenic Microorganisms: bacteria
transformed w/ human genes produce
pharmaceutical compounds like insulin
Transgenic Animals: Have been used to
study how human genes function
•

EX: Mice are created with human-like immune
systems
Transgenic Plants: Have been important to
increasing the food supply.
•
EX : Plants have genes that code for natural
insecticides
13-4 Applications of Genetic
Engineering
Clone: Member of a population of
genetically identical cells produced from
a single cell.
EX: a bacterium taken from a
bacterial colony
First Mammal cloned was Dolly- a sheep
cloned in Scotland in 1997