Irradiated Seed Lab

1

• Irradiated Seed Lab
• Today you will be planting marigold seeds that
  have been treated with gamma (?) radiation. You
  will compare the growth of your seeds with a
  batch of control (untreated) marigold seeds. You
  will observe the plants for 3 weeks.
• 2. Obtain the following from the cart
• Flat
• Potting mix to fill your flat 2/3 of the way full
• Plastic bag
• Permanent marker
• 3. Obtain ½ packet of seeds
• Your team must split a packet in half
  with another team from another table. Be sure to
  record the lot code on your lab sheet and on your
  flat! Count out and divide the seeds as evenly
  as possible with the other team.
• 5. Follow the planting instructions on your
  Student Guide.
• 5. YOUR HOMEWORK Write a hypothesis that
  predict the types of anomalies that you might
  find in your plants as they germinate and grow.
  Use if/then statements. State the independent
  and dependent variables. Identify the
  control(s). Your hypothesis should be
  word-processed.

2
Background

• The seeds used in this lab were treated with
  gamma (?) radiation. Gamma rays are of short
  wavelength, high energy, and readily penetrate
  most matter. They are a form of ionizing
  radiation (other forms of ionizing radiation
  include alpha, beta, and x-rays).
• When ionizing radiation passes through matter,
  its high energy level causes some electrons (from
  the atoms composing the matter) to be ejected
  from their orbits. This means that the atoms are
  no longer neutral they are positively charged,
  or positive ions. Ionized atoms may react
  chemically with other atoms in the molecule and
  or other molecules. If this molecule is part of
  a gene, the chemical change may alter the code in
  that gene.
• Ionizing radiation can cause hereditary changes
  (mutations) in living things. Most mutations
  induced by high-energy radiation are harmful.
  Very few induced mutations are considered
  desirable
• (From Carolina Biological Supply Company,
  Irradiated Seed BioKits)

3

• IRRADIATED SEED LAB
• VII. Results and Data
• Data table of your plant height over time
• Table of class average plant height
• Graph of class average plant height
• Drawings (labeled)
• VIII. Conclusion
• Restate the hypothesis, in the past tense
• Summarize findings
• Compare the results with what was predicted
• Error analysis
• Suggest improvements and/or suggest further
  research