BSC1005LReadings
Read the textbook chapter and chapter narrative. Go to the process
of science website. Read through all of the
webpages, including those about preliminary observations,questions,
hypotheses, predictions, and tests. On every
page you will need to go to click on the link at the end of the readings
to proceed to the next page. You can ignore
the link options at the bottom of each page.
Materials Needed
plastic tray or plate, plastic wrap
paper towel, water
package of radish seeds
microwave oven
ruler, pencil, graph paper
General Laboratory Question
What is the effect of increasing exposure times of microwave radiation
on radish seed germination? What is the
effect of increasing exposure times of microwave radiation on radish
seed sprout length?
Part 1.
Form a hypothesis
1. Consider the questions above.
2. Write a hypothesis (prediction)for each question, in the below space.
3. Make sure they are clear and testable!
Use the If(statement about observations)...then (prediction of results
of experiment)... format.
For instance, If I drop a pencil, then it will fall.
Part 2.
Procedure to test hypothesis
1. Prepare six plastic germination chambers by folding the paper towel
into the bottom of a
plate, pan or tray and moisten the paper towel in each chamber.
2.Separate the radish seeds in the package into 6 groups of at least
ten (10) intact seeds in
each group. Place each group of seeds into the microwave oven for a
different amount of time.
Use times of 0 sec, 10 sec, 20 sec 40 sec, 80 sec and 120 sec.
3. Place each group in a separate chamber and write the length of time
the seeds were
exposed to microwave radiation on the plastic chamber. Also write down
the date of the
beginning of the experiment.
4. Cover the seeds and the moistened paper towel to keep in the moisture
during the next 6
days. You may need to add a few drops of water if the towel gets dry
during the experiment.
5. Store the plastic plates where they will not be disturbed, but in
the light.
Answer the following questions for this experimental setting.
1. What is the independent variable?
2. What is the dependent variable?
3. Which of the groups of seeds would be the control group for this
experiment?
Part 3.
Results of test.
1. Observe the radish seeds in your plastic dish daily for a "sprout"
or leaflets coming out of
the seed. Note: there may also be fine, white hairlike rootlets-ignore
those.
2. On the sixth day you are to COUNT the number of seeds that you can
see the "sprout"
coming out of the seed--even if the sprout is very small. Don't count
them if the outside coat of
the seed has broken open but there is no "sprout."
3. RECORD the number of seeds germinated for each group on the sixth
day. CALCULATE
the average percent of seeds that germinated by the sixth day for each
exposure
time.
PRODUCE a table with the percentage data and REPORT that information
below.
Part 4.
Results continued.
4. MEASURE the length of the sprouts, in millimeters (mm), for each
sprouted seed for each
group on the sixth day. CALCULATE average sprout length for each time
exposure. Make
sure you identify the mm marks on the ruler- there are 25 mm in an
inch and a mm is about the
width of a period (.)
5. PRODUCE a table of the data and REPORT that data below.
Part 5.
Reporting and plotting the data.
1.Click here to REPORT both of your germination and sprout information
so all laboratory
participants can observe your data.
We will soon be discussing all of the data, from all participants,
on the bulletin board.
2. On a separate piece of blank, white graph paper, construct two XY
graphs (see Figure
8.20C in textbook for example) of your data: one that compares the
average percent of seeds
that germinated to exposure time and another that compares sprout lenght
to exposure time.
Convention dictates that you label the horizontal or X axis as the
independent variable and the
vertical or Y axis as the dependent variable. Make sure you use label
both axes with relevant
numbers and label each graph .
3. Print and sign your name on the graphs and then FAX both the graphs
to the instructor.
Please write boldly so the FAX will be legible.
Neatness counts!
Part 6.
Discussing the data.
4. In the space below, indicate if the data supports or does not support
your
prediction (hypothesis).
5. Using your data, discuss your conclusions concerning the effect
of microwave exposure on:
1)germination rates and 2)sprout lengths.