KEY
Note Taking Guide 1
Topic # 3034
Mutations
Torey Birchmeier
I.
Mutations
A.
A sudden change in the characteristics of an organism due to a change in
the chemical structure of the DNA.
B.
The change must be capable of being transmitted fully to future generations
without change.
C.
An example of a mutation is the polled characteristic in beef cattle.
II.
Causes of Mutations
A.
An error in DNA replication
B.
Exposure to radiation
C.
Exposure to certain toxic or poisonous chemicals
D.
Other genetic abnormalities such as extra chromosomes or chromosomes
crossing or breaking
III.
Mutations in Evolution
A.
Mutations are recognized as the primary source of the hereditary variations
that make evolution possible.
B.
Mutations can either be harmful or useful to species.
C.
Mutations that help an animal survive are continued because survivors
reproduce and pass the gene on to their offspring.
D.
Mutations that are harmful to a species are less likely to be passed on
because the animals do not survive or reproduce.
Mutations in Commercial Agriculture
A.
Perfect Example……..
B.
A natural occurring mutation or change occurred in the horse.
C.
Over many years the horse’s hoof characteristics changed to suit a
changing environment.
D.
The one hoofed horse today is much more useful to agriculture than its
smaller four toed counterpart “eohippus” which lived long ago.
IV.
V.
Other Mutation Examples
A.
Rust resistant wheat
B.
Plant breeders have taken advantage of natural selection for a strain of
rust resistant in wheat.
C.
Breeders have breed this trait into other wheat strains to help aid in
agriculture production
D.
E.
F.
High protein corn
Geneticists have selected for high protein varieties and have tried to breed
them exclusively
This selection is “manmade” rather than based on “natural selection” such
as the horse