BACKGROUND:
Seeds come in many different shapes
and sizes. A seed is the "baby" plant in waiting.
The purpose of the seed coat is
primarily to protect the embryo (or baby) plant against such hazards as
excessive drying, mechanical injury, and the digestive juices of animals
(if it is eaten). Many seed coats are impermeable to water or oxygen or
are hard which helps it remain "asleep" or dormant for a long
time. When the conditions are right the dormant seed will grow. Seed
coats are frequently specialized and may facilitate dispersal by wind or
animals. The winged seeds of some species are familiar examples of
wind-dispersed types. In some plants, the seed coat is adhesive (as in
mistletoe) or becomes gummy when wet (as in mustard seeds) and adheres
to the feet of birds. Hairy seeds may cling to the bodies of animals and
be transported for long distances.
Seeds are used by other organisms as
food, because seeds have food stored in them. Seeds furnish humans with
great proportions of food. A large part of the world relies on the
grains of wheat, rice, soybeans, corn, rye, and barley. Oils and fats
are produced from the seeds of coconut, corn, cotton, flax, castor bean,
sesame, peanut, and soybean. Oil from the cotton seed and peanut is
utilized in the manufacture of various products such as butter and lard
substitutes and soap. Linseed oil from flax seed is used in the
manufacture of paints, varnishes, artificial leather, oilcloth, and
linoleum.
PROCEDURE:
- In this lab students will be
looking at the overall seed, but will mainly classify, compare, and
describe the seed coat. Seed coats come in many different sizes and
different textures. The key portion of this lab is to look at the
different seeds and try to point out what the plant looks like.
Instruct students to classify or sort the
seeds into groups that look similar in shape. Then have them look at the
outside of the seeds and see if they are smooth or wrinkled.
- Instruct the students to count how
many seeds they have of the same kind. You may want students to record
the information on the worksheet. Let them use their imagination when
naming the seed, however they may just use color to separate them.
If your kindergarten child can write, use the worksheet. If
not, you might want the child to take one seed and paste it on a
piece of paper to show the different types of seeds they
found.
- Different pictures of seeds can be
seen on several web sites. To keep current, we recommend you do a search
on "seeds" to help find more pictures.
