Download Genetic Technology

Genetic Technology
Ch. 13
Selective Breeding

Selecting the most desired
traits to serve as parents of
the next generation
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Used for plants and
animals
Ex: Cows in 1947
produced an average of
4,997 lbs of milk; in 1997,
a cow produced an
average of 16,915 lbs of
milk per year.
Inbreeding
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Used to ensure that breeds
consistently exhibit a trait and
eliminate undesired traits.
Mating of closely related
individuals
Can bring out harmful,
recessive traits because of
greater chance that related
individuals may both carry
recessive allele.
Hybrids
Crosses of two different purebred
individuals can produce bigger and
better offspring
 Ex: plants that are disease resistant can
be crossed with others to produce larger
and more numerous fruit.
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Determining Genotypes

Must be careful selecting genotypes
to ensure the undesired recessive
trait is not present.
 Use test cross to determine
genotypes
 Cross an unknown individual with
an individual of known genotype
(i.e. homozygous recessive) and
observe the offspring phenotypes
Think, Pair, Share
If you were not sure of your genotype
and you have brown hair, what
genotype individual would you need to
perform a test cross with to determine
your genotype?
 Draw a punnett square and determine
what ratio of genotypes your offspring
would have.
 If you did not have any blonde hair
children, what does that mean your
genotype must be?

Genetic Engineering
Faster and more reliable method for
increasing the frequency of specific
alleles in a population.
 Involves cutting/cleaving DNA from one
organism into small fragments and
inserting them into a host organism of
the same or different species.
 aka: recombinant DNA technology
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Transgenic Organisms
Plants and animals with functional
recombinant DNA are transgenic
organisms.
 Recombinant DNA inserted in a host
organism’s chromosomes will be used
as if it were its own DNA.

Applications of DNA
Technology
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Recombinant bacteria break down pollutants (oil) into
harmless products.
Recombinant bacteria can produce human growth
hormone to treat dwarfism, and insulin to treat diabetes.
Transgenic animals are used to study human
chromosomes so that scientists can learn how to treat
diseases in humans.
Recombinant bacteria used on crops can prevent frost
damage.
Plants have been genetically engineered to resist
herbicides, produce internal pesticides, or increase their
protein production.
Applications in Humans
Diagnosis of genetic disorders may be
made before birth.
 Gene therapy can insert normal genes
into human cells to correct genetic
disorders.
 DNA fingerprinting and DNA samples
(blood, hair, skin, or fluids) can be
used to convict criminals.
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Gene Therapy