Chapter 13 Genetic Engineering


14 Δεκ 2012 (πριν από 4 χρόνια και 6 μήνες)

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Chapter 13 Genetic Engineering

Selective Breeding

choosing what parents you
want to produce offspring for the next

What do get when you cross a bull dog and a


Crossing dissimilar individuals to
bring together the best of both organisms.

Hybrid Vigor

phenomenon, offspring are better
than the parents.

Inbreeding is the continued breeding of
individuals with similar characteristics.

Risky, because it could bring out the
recessive alleles and cause a genetic defect.

Blindness, joint problems

Increase Variation

Why would humans want to increase

Better the species

Make the mutation occur faster

More variety

Manipulating DNA

Scientist change DNA by

Extracting DNA from cells

Cut into smaller pieces

Identify the sequence of bases on the DNA

Make unlimitied copies of DNA

DNA Extraction

Cells are opened up and DNA is
separated from other parts of the cell

Cutting DNA

DNA is cut into small fragments by
restriction enzymes. (Cuts DNA at a
specific nucleotide sequence…very

Separating DNA

Gel Electrophoresis

DNA Fragments are
placed in certain gel wells and an electric
voltage is passed through them.

DNA molecules move toward the opposite
end of the gel.

Smaller DNA fragments move faster
through the gel.

Using the DNA Sequence

The DNA Sequence can be read, studied,
or changed.

Compare genes with other organisms.

Recombinant DNA

produced by
combining DNA from different sources.

Making Copies

In order to study genes, it helps to make

PCR (Polymerase Chain Reaction)

makes many copies of DNA through a
process of heating and cooling using DNA

13.4 Applications of Genetic

Transgenic Organisms

organisms contain
genes from other organisms.

Example: The enzyme (luciferase) from fire
flies was transferred into a tobacco plant cell.

What do you think happens?

The plant glows at dark…page 331

Why make transgenic organisms?

Resist pests, herbicides, harsh conditions

Improve nutritional value, shelf life

Test and study

Medical purposes…insulin, growth
hormone, clotting factors

Transgenic Animals can produce more
milk, less fat, human proteins


Cloning is producing genetically identical
cells from a single cell.

Bacteria is easy to clone (unicellular)

What about multicellular organisms?

Ian Wilmut cloned the first sheep. DOLLY.

Cloning Process

To Clone or Not to Clone?