Lab 6:  Seeds

In this lab you will apply the information you learned so far in your Botany class as well as the materials from the Chapter of Fruits and Seeds.  You will examine a set of seeds presented and determine how you, as a Scientist, would develop a lab about seeds with these "ingredients".

At the end of this lab the successful student will be able to match raw materials (seeds) with potential actions to learn more in a scientific method about seeds and germination. You may propose any plan for this lab that you think would be interesting and for which you can get the seeds.  Here are some examples from previous years plus some ideas you can use.

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Seed germination under different conditions

Here a student makes plans for what he will do.  He is using different types of hormones and carefully measuring their impact on the germination of his seeds and the early growth of the plant.

He is also experimenting with different types of growing containers to see if identical treatment of the seed with identical soil will produce different results given different types of containers.

 

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Propagation

This student is writing up his plan to propagate pineapple plants.  He went to the local grocery store and got 10 pineapple TOPS that were cut off when the grocery cored the pineapples to sell just the "meat" of the pineapple plant.

He is doing 4 batches:

Which do you predict grow the best?  Why?

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Soil in the terrarium

This student decided to build a terrarium.  He put plain topsoil on one side and potting soil on the other.  He then sealed the terrarium and waited for the seeds to grow before adding animals.  What problem do you think he had to handle since he did not use sterilized top soil?  Do you think it was difficult to handle that problem?  What effect would putting some moss plants into the terrarium at the start of the experiment have on the possible outcome?  What about larger plants?  Would the shade they made make a difference?  Could that be compensated for in the student's experiment?

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Bird Seed Experiment

Materials:

Procedure:

  1. Put a paper towel into a baggie, keeping it flat. You may have to fold the edges if it is too long.
  2. Staple across the bottom of the baggie about 1 inch from the bottom. Put staples very close together
  3. Add your watering solution. Be sure to pour it down the side where the small opening is, otherwise it comes out the small staple holes.
  4. Add 100 seeds selected randomly from the birdseed mixture. Spread them out evenly along the staples.
  5. Seal the Ziplock
  6. Label the top of the baggie with your watering solution.
  7. Staple the baggie to a bulletin board or tape the baggie to a window.
  8. Once the seeds start sprouting (only a couple of days) take the baggie apart and count the number of seeds out of 100 that germinate. This number is called the seed viability.

To have a controlled experiment,  use water as your watering solution in one baggie. To compare other watering solutions to just water you need to repeat the process above with: fertilizer solutions, various hormone solutions, or other solutions based on research at your garden store or from web sites that discuss germination aids. In this way you can compare the effect of fertilizers, salt solutions, polluted water, soapy water or other solutions to the control using water.

Set up an experiment using water as a control and at least one other watering solution.  Predict the results ... which will give the most germination?  Why?  Compare your results and make conclusions. Do the results support your prediction?  Send this along by with a scanned photograph of your set up to your instructor.

If you would like to learn more, continue the experiment after germination by opening up the baggy to make some space and allowing the seeds to continue to grow.  Make predictions.  Once the baggie is opened, you will need to continue to add the same amount of the different solutions to the different open baggies to keep the seeds from drying out.  You may want to move the baggies to the terrarium environment (see the next item for directions for the terrarium) for a more controlled experiment.  How does the development of the seedlings differ from the baggies with different solutions?  Note in a terrarium environment you will NOT need to continue to add measured amounts of your solutions.

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Terrarium Experiment

Materials needed:

Procedure:

If you are going to build a terrarium, follow the steps very carefully. The success of this balanced ecosystem relies on very careful construction. Check out the websites listed below for more on building a terrarium. On completion of your terrarium, photograph it in several views and email these to your instructor for credit.

  1. Clean out a glass gallon jar. Only use water (no soap) and dry it out with paper towels after washing it.
  2. Put in one cup of gravel in a pan and run water over the gravel to clean it, much like panning for gold! Drain the water and dump the gravel onto paper toweling. Put another towel on top of the gravel and pat it to remove excess water. Using you hand, carefully place the gravel in the bottom of you glass jar. Follow the same procedure with more gravel if necessary to get about a one-inch gravel base.
  3. Rinse out your Ziplock bag and place two cups of soil (good potting soil will do but you can actually purchase terrarium soil). Add ˝ cup of water to the Ziplock bag and soil. Zips the bags closed and mix the soil and water until the soil is good and moist (not runny). Place this mixture (with your hand) over the gravel in the bottom of your gallon jar.
  4. Take the jar and the trowel (or a large spoon) outside and collect good rich soil from a rather damp area. Fill the gallon jar with soil so that the total base is no more than ˝ the depth of the jar. You may mix the two soils together—this is your choice.
  5. If you are doing this for the seed and germination project, you need to select appropriate seeds to plant. Think carefully. What will be small enough when germinated to do well in the confined area? If you are doing this for your final project collect three to four plants that easily fit into your aquarium. Moss may be a used, even small ferns or clover as long as it is small enough is also good choices. Avoid flowering plants that have large flowers. Wintergreen also does well in a terrarium.
  6. Place the seeds or plants that you have selected and carefully plant them in the soil within your jar.
  7. Locate a few small animals to add to your aquarium such as small insects, worms, larval stages of insects, spiders, millipedes, centipedes, etc. are all good forms to use. DO NOT OVERLOAD THE TERRARIUM WITH ANIMAL LIFE. There will be life in the soil that you are unknowingly adding to it.
  8. Stretch a plastic wrap over the top of your gallon jar. Secure the plastic wrap with a rubber band.
  9. To maintain your terrarium, place the jar where you can alternate the days too leave it in the sun.

Check out these websites on terrariums

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Last modified: October 08, 2004 by Cynthia Herbrandson  © Copyright 1999, Kellogg Community College. All rights reserved.