Investigation 1 part 3 “Seed Soak” Origin of Seeds Investigation 1 part 3 “Seed Soak”

Changes to Seeds Observe the changes to the seeds in the minisprouters. Share your observations.

Inquiry Introduction An important part of science is asking questions about the things we observe and try to set up an investigation that will help answer those questions. What could be causing the seeds to appear swollen? If the seeds are soaking up water, how can we find out how much water the seeds are holding?

Guide the Investigation Share your ideas on how we could investigate these questions. I have some equipment that will help you find answers. balance dry lima bean seeds

Questions to Think About What are some ways we could measure the seeds? What should we compare the soaked seeds to?

Investigation (cont.) Weigh 5 dry lima bean seeds. Soak the seeds. Weigh them again to find out how much water the seeds absorb. Teacher demonstrate. Make sure everyone in your group gets a turn to use the balance. Record your observations on The Soaked Seed student sheet.

Share Results Share the results. Questions to think about: Does it make a difference where the beans or the gram pieces are placed in the cups? Does it make a difference if the gram pieces are gently placed or dropped into the cups?

Procedure and Record Weigh the beans once more. This time, record the mass on the bottom of your Sprouting Seed student sheet. I will be assessing your technique tomorrow as you weigh the soaked beans.

Add Water and Store We will add enough water to the cups so that the beans are just covered. Stack the bean cups on tops of the minisprouter and store them until next session. Leave all the gram pieces in 1 cup on the table.

Return Equipment Clean up all materials. Check under the chairs and tables. Sit quietly so I know you are ready to move on.

We will continue this investigation during our next session. BREAKPOINT We will continue this investigation during our next session.

Retrieve Place Mats One person from your group please come retrieve your group’s place mat. Carefully walk it back to your table.

Changes to the Seeds Observe the changes to the seeds in your minisprouters. Discuss the changes to your soaked lima beans with your group members and table mates. Estimate how much the beans have swelled. Do you estimate the beans to be the same size, twice as big, or more than twice as big as the dry beans?

Drain the Sprouters Drain the minisprouters into the big basins on your tables. If you accidentally splash or spill, please grab some paper towels and clean it up.

Weigh the Soaked Beans I will be walking around watching you weigh the soaked beans. Weigh 5 dry lima bean seeds. Soak the seeds. Weigh them again to find out how much water the seeds absorb. Make sure everyone in your group gets a turn to use the balance. Record your observations on The Soaked Seed student sheet.

Share Results To find out how much water the beans soaked up use the following equation: Mass of the soaked beans – mass of dry beans Was anyone surprised by the result? Why do you think the seeds soak up so much water?

Open the Lima Beans Carefully open the soaked beans. Examine the structures inside using the hand lenses. Remove the thin outer coating on the seed. Open the 2 halves of the seed. Using the hand lens, examine the inside surfaces of the seed. Share your observations.

Seed Coat  The thin white shell that comes off the seed is the seed coat.

embryo Along the narrow end of one side of the cotyledon, you will find a baby plant called an embryo. Everything will be the same white color, so it will take careful observations to see the embryo.

cotyledons The two halves of the seeds are cotyledons. The been has 2 cotyledons and is called a dicot. Corn has one cotyledon so it is a monocot. The cotyledon is part of the seed that stores the food for the young plant.

Return Equipment Throw out the seeds. Clean up all materials. Check under the chairs and tables. Sit quietly so I know you are ready to move on.

Word Bank Entries embryo seed coat cotyledon

embryo The undeveloped plant within a seed. (light green)

The outer covering of a seed. seed coat The outer covering of a seed. (brown portion)

cotyledon The “seed leaf” that provides the germinated seed with food. (peach/beige color)

Is a sees alive? How can you tell?? Content Chart Entries Is a sees alive? How can you tell?? What is inside a seed?

What We Learned Seeds begin to grow and develop when placed in water. A seed holds food for the plant embryo.

Let’s Read! Open your book. Find the science story called Barbara McClintock. Follow along while the computer reads aloud the story.

Questions?