Download Lets have a bal Student Lab

Let’s have a bal!
Student Laboratory
Name________________________________
Date_______
Partner(s)_____________________________________________________________________________
Background:
When scientists mapped the Human Genome in 2001, it was viewed as the beginning of a new
era. Now that we know every A,T, C and G it takes to build a human; it won’t be long before we have
cures for everything from Alzheimer’s to Cancer. Now we know that the bases of our DNA are just like
words on a page. How they are read is just as important as what they are. Plants turn yellow when
they’re kept in the dark even though they have the genes for chlorophyll; some identical twins don’t
look exactly alike even though they have exactly the same genes; and you have genes for building bones
in your eyeballs. WHY?
It turns out there is more going on than just our genes. The science of Epigenetics studies what
is going on “above” our genes. How are they controlled? When are they turned on? Why are they
turned off? What role does the environment play? Can parents pass down changes in the controls
without there being changes in the genes? Epigenetic scientists are trying to answer these questions.
Often when scientists want to study something, they will use a Model Organism, something that
can be easily grown, makes lots of offspring, and has clear characteristics. Scientists at the Boyce
Thompson Institute at Cornell University are using the model plant Arabidopsis thaliana to study
epigenetics. You will be growing Arabidopsis plants, and looking out for strange looking plants that may
be a sign of an Epigenetic mechanism. If you find any, the scientists at BTI want the seeds from those
plants so they can study them further.
Purpose:
To participate in an on-going scientific experiment by growing and documenting lines of
Arabidopsis thaliana that are known to contain epimutations.
Materials
Grow trays with domes
Rulers
Soil: Miracle Grow Potting Mix with Micromax
Plant Stakes
4 X 4 cell pot insert
3ml pipettes
Water
Environmental monitors
Arabidopsis seeds sent from BTI
Procedure
Planting Day:
1. Fill 4 cells completely with soil.
2. Label one wooden stake with the teacher’s name and your seed’s line number on the front, and
students’ names and planting date on the back. Place the stake in the upper left cell.
3. Cut out square of filter paper with seed in the middle of square (~1 cm by 1 cm).
4. Using tweezers, place the seed square in the middle of a cell.
5. Lightly cover the seed square with soil (you do not want the seed deeply buried in the soil).
6. Add 6 ml of water to the top of the cell.
7. Bring your 4 X 4 cell insert to the teacher for placement in the tray.
8. Record the date, temperature (oC), % humidity, and light level (lux) on your data sheet.
Let’s have a bal!
2 Weeks after planting:
Record number of plants growing, temperature, humidity, lux level, and date.
4 Weeks after planting:
1. Record number of plants growing, temperature, humidity, lux level, and date.
2. Measure and record the longest chord on each plants’ rosette. You do this
By placing one end of a string on the tip of the longest leaf on the plant, and
pulling the string to the tip of whichever other leaf gives you the longest
line. Lay the string on top of a ruler, and record this chord’s length in cm.
4 X 4 cell insert layout
3. For each plant, record some detailed observations regarding
the appearance of the plant in the area labeled “Qualitative
Observations”. For example, compared to the other plants, is
this plant smaller; does it have very curly leaves; is it missing
bristles on its leaves; is it a different color; does it have a taller
flower structure; does it have less leaves?
How to measure a chord
4. If you think one or more of your plants is very different from the others, it may be a mutant. Show the
plant to your teacher. If it is determined to be a mutant, it will be set aside and allowed to grow for
several more weeks. Once it has flowered and produced seeds, the seeds will be sent to the scientists at
BTI for further study.
Questions:
1. Did you have any problems planting the seeds, growing the plants, or making observations? ______
If so, what were they, and how might they have affected your results?
2. What was the purpose of growing Wild Type and bal mutants?
3. How many of the plants appeared to be Wild Type? _______
How many appeared to be mutants? ________
4. Did some Arabidopsis line numbers make more mutants than others? _________ Why do you think
this is?
Let’s have a bal!
Student Data Sheet
Name__________________________________
A.thaliana line___________________
Partner (s)______________________________
Teacher_________________________
Environmental Data
Date
Temp 0C
% Humidity
Lux
Number
Viable
Planted
2 Weeks
Post Plant
4 Weeks
Post Plant
Observational Data (at Bolting)
Chord Length
(cm)
Date________________
Qualitative
Observations
Mutant?
y/n