Tuesday, July 14, 2015

// // Leave a Comment

Dissect a Bean Seed Lab!

It's time to dissect a bean!  Beans are perfect to study and learn more about how seeds work!

We dissected beans as part of our Nature Club and for a botany lesson.  You could include it in a seeds or plants unit, a letter "S" day, or just for fun!  They are super flexible, provide a fantastic science lab, and are fascinating for young children.  Keep reading for tips for your own bean dissection lab, the parts of a bean, and a free printable!

Simple Supplies for a Bean Dissection Lab:

* prepared beans
* plastic knives
* optional: magnifying glasses
* optional: permanent markers
* optional: Dissect a Bean printable

Easy How To:

1.  Prepare your beans!  This needs to start at least 12 hours in advance.  Soak the dry beans of your choice for 12-24 hours.  Rinse them at least every 12 hours.  We used an assorted soup mix of beans, and most of them worked wonderfully.  If you're going to choose only one, the red kidney beans were particularly easy to work with.  Soaking the beans softens the hard seed coat and fills the bean with water.  This makes it much easier for little hands to dissect!

Extra Tip:  Two days before your lab, soak a batch of seeds.  Rinse them after 12 hours and let them soak another 12 hours.  Rinse them again, and spread them out on a paper towel.  Continue to re-rinse them every 12 hours so you have a batch of sprouted bean seeds!  Then, one day before your lab, soak another batch of seeds.  Rinse them after 12 hours and let them soak another 12 hours.  These will be soft and easy to dissect, but unlikely to have little radicles (baby roots or sprouts) growing out of them.  Let your kiddos compare the two batches!

This picture (below) is the first batch of beans I started (two days before the lab).  I absolutely love this picture!!  Notice that the radicles have sprouted out of the beans and are already beginning to grow into little roots!

2.  Before dissecting the beans, we talked about seeds.  First review the parts of a plant (roots, stem, leaves, flower), and then talk about how plants make flowers to prepare for the seeds.  After the flower is done blooming, it will wither and dry and turn into seeds for the plant.  We looked at different kinds of seeds and talked about the plants they came from.  Some of the most stunning were some flowers, tall grasses, and avocados.  We also talked about seeds we've seen in foods we've eaten.

Here is an avocado seed we looked at.  It had been drying for almost a week and was very easy to crack in half with a plastic butter knife.  You can easily see the dark seed coat on the outside, the avocado embryo on the inside, and the cotyledon (food supply) surrounding the embryo.

We also looked at flowers and talked about how they change into seeds when they are done blooming:

3.  Demonstrate the bean dissection.  We do the actual lab outside, mostly because I think it is wonderful for the kids to work outdoors.  It can easily be done inside also.

Slide the bean coat off:

Use the knife to carefully cut the bean in half.  The swollen, soaked beans will often start to split right down the middle where it is easiest to find the bean embryo.  If you cut the "wrong" way, you can easily cut it again to see the embryo.  This will be excellent fine motor exercise for your kiddos!

The bean embryo looks like a "baby bean."  The rest of the bean is the cotyledon, or food for the baby bean.

4.  Pass out the beans, plastic knives, and any optional materials you're using.  Let your children dissect the beans and look for the bean embryo!  You may want to let them color it with the permanent markers, examine them with the magnifying glasses, or draw pictures of them on the bean dissection printable.  Or, if you used an assortment of beans, they will probably want to dissect several different types and compare them!  What is similar and what is different?

Here is a close-up of a radicle popping out of the bean (the radicle is the part of the embryo that becomes the root).

Examining the beans with a magnifying glass:

Dissecting the bean!  Opening up the bean is more like wedging open drawer than actually cutting, but the plastic knives work wonderfully!

And another close-up of what you will see inside the bean seed:

5.  When you're done studying the beans, you can plant them and watch them grow or cook the unused beans and eat them!  Both are loads of fun!

Have you dissected beans before?  I'd love to know!

Amazon Affiliate Links:

I may share at any of these parties!

Never miss another post again!  Sign up for our weekly updates newsletter and get links to all our posts once a week in your inbox!  Sign up here!!