+

Origin of SeedsInvestigation 1 part 3 “Seed Soak”

+ Changes to SeedsObserve the changes to the seeds in the minisprouters.

Share your observations.

+ Inquiry IntroductionAn 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 InvestigationShare your ideas on

how we could investigate these questions.

I have some equipment that will help you find answers.balancedry lima bean seeds

+ Questions to Think AboutWhat 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 ResultsShare 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 RecordWeigh 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 StoreWe 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 EquipmentClean up all

materials.

Check under the chairs and tables.

Sit quietly so I know you are ready to move on.

+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 SeedsObserve 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 SproutersDrain 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 BeansI 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 ResultsTo 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 BeansCarefully 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.

+ embryoAlong 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.

+ cotyledonsThe 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 EquipmentThrow 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 Entriesembryo

seed coat

cotyledo

n

+ embryoThe undeveloped plant within a seed. (light green)

+ seed coat

The outer covering of a seed. (brown portion)

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

+Content Chart EntriesIs a sees alive? How can you tell??

What is inside a seed?

+What We LearnedSeeds 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?