Monstrous Mutations [pic]
Introduction:
Mutations are caused by changes in DNA. Knowing a few basic types of
mutations can help you understand why some mutations have major effects and
some may have no effect at all. The following are some of the types of
mutations that can occur.
Substitution
A substitution is a mutation that exchanges one base for another (i.e., a
change in a single "chemical letter" such as switching an A to a G). Such
a substitution could:
1. Change a codon to one that encodes a different amino acid and cause a
small change in the protein produced. For example, sickle cell anemia
is caused by a substitution in the beta-hemoglobin gene, which alters
a single amino acid in the protein produced.
2. Change a codon to one that encodes the same amino acid and causes no
change in the protein produced. These are called silent mutations.
3. Change an amino-acid-coding codon to a single "stop" codon and cause
an incomplete protein. This can have serious effects since the
incomplete protein probably won't function.



Insertion
Insertions are mutations in which extra base pairs are inserted into a new
place in the DNA.


Deletion
Deletions are mutations in which a section of DNA is lost, or deleted.



Frameshift
Since protein-coding DNA is divided into codons three bases long,
insertions and deletions can alter a gene so that its message is no longer
correctly parsed. These changes are called frameshifts.
For example, consider the sentence, "The fat cat sat." Each word
represents a codon. If we delete the first letter and parse the sentence
in the same way, it doesn't make sense.
In frameshifts, a similar error occurs at the DNA level, causing the codons
to be parsed incorrectly. This usually generates proteins that are as
useless as "hef atc ats at" is uninformative.


Objective(s):
. To understand and observe mutations.
. To recognize and adapt to mutations
. To observe how mutations effect survival skills

Materials Needed:
|Nine dry peanuts in shell (per group of three students) |
|Blanket for the peanuts |
|Table or desk |
|One cup (per group of three students) |
|15 plastic knives |
|Six pairs of goggles |
|Cotton |
|Stop watch |
|Large roll of duct tape or masking tape |
|String |
|Paper bag containing the letters A through H on slips of paper |

Procedure:
1. Students should form groups of threes. Each student will simulate an
animal that can only digest peanuts as its food source.
2. Unfortunately, random mutations have produced some unusual
characteristics in recent offspring. Each group will find out what
mutation they represent by selecting a letter from the paper bag the
teacher has provided.
3. The letter drawn will correspond to the characteristics listed in
Chart 1. This letter will also represent the letter of each group's
home location and storage cup.


Chart 1
|Letter drawn by |Characteristic produced by mutation |
|groups | |
|A |Long fingernails (produced by plastic |
| |knives taped to fingers with tape) |
|B |No fingers (produced by taping each hand|
| |closed) |
|C |Lack of peripheral vision (produced by |
| |putting on goggles and stuffing cotton |
| |in the sides to prevent viewing from the|
| |side) |
|D |Hands fused together in front of body |
| |(produced by placing hands together in |
| |front of body and taping them together) |
|E |Feet and ankles fused together (produced|
| |by taping the ankles tightly together |
| |with tape) |
|F |No arms (produced y taping the arms down|
| |to the side of the body with tape) |
|G |Arms fused together behind the back at |
| |the wrists (produced by placing arms |
| |behind the back and taping tightly at |
| |the wrists) |
|H |Blind (produced by using goggles taped |
| |over securely with tape) |


Each group should attain the proper materials and prepare itself to
represent the characteristic produced by the letter of the mutation
selected from the paper bag.
5. Each group should begin the activity at the specified location in Figure
A. The goals of each group are to:
A. Gather the food (nine peanuts per group)
B. Store the food for later use (place the nine peanuts in your letter-
designated container).
C. Retrieve the food at a later time (remove the nine peanuts from the
container and return with the peanuts to the home location).
D. Process and consume the food (remove the peanuts from the nine
shells and consume these peanuts).
6. To begin