Life Cycle - Plants (1A)
Pre Lab 
  • Comparing different types of seeds.
  • Distinguishing the components of a bean, corn, and fern. 
  • germination
  • seed coat
  • seed
  • spore

Students use a worksheet examine the parts of seeds.


Plants are an important food source for animals. Plants, like all other organisms, have developed unique strategies for reproduction. Most plants produce seeds, which are plants waiting to grow but which have the capacity to wait a long time before they begin the growth cycle.

Seeds may be scattered by wind, water, animals, or propulsion. Animals may spread seeds by a variety of ways such as by eating hard seeds which pass through the animal's digestive system unharmed or by picking up seeds on their coats and feathers. The propulsion method results when the seed covering opens in such a way that the seed shoots out. In many cases it is possible to look at a seed and figure out which method is used. For instance, if a seed has feathery extensions (like dandelions), then it can be sail through the wind, looking for a suitable place to germinate (grow).

The first step in seed germination is the absorption of water through a small opening called the micropyle. The introduction of water through the pore causes the seed to swell. Placing a bit of candle wax over the pore will demonstrate that the seed will not swell when introduced into water. Many seeds will swell dramatically as the water enters, and you will notice a sweet, almost fermenting odor in the water after seeds have been soaked overnight (this is from enzyme action).

Ferns reproduce through primitive "seeds" called spores which are produced by the small pumps on the back of older leaves. The dark brown, tiny spores are single cells that will develop into plants if they land in the perfect environment. Seeds are more likely to produce plants in environments that are less than perfect. Spore producing plants produce tremendous numbers of spores in order to have just a few develop into plants.


The protective seed coat, food storage area and partially developed plant can all be seen reasonably well in a pea, bean, or peanut. A corn seed is constructed differently and should be discussed to illustrate that not all seeds are the same.

  1.  Instruct students to color the roots brown, food storage yellow, and leaves green on the worksheet (this will help when you discuss each of the pictures.
  2. If you have different types of fruit, you may want the students to try and observe where the seed is located.  Look at the "Fruit and Seed Classification" chart and guide students observation of where the seeds are located.  You may want to give them the names to help students see the difference of where the seeds are located.
  3. Instruct students to look at the bean seed. The first step in seed germination is the absorption of water through a small opening called the micropyle (hole that water penetrates the seed through). If you have bean seeds available show your students where this hole is located. Explain that the rest of the bean functions as food storage to help the seed make a leaf, which in turn will produce its own food.
  4. You may want to put the beans in water and have the students observe that the bean actually gets larger because of the water entering through the micropyle
  5. Show the students a corn seed. Note that the shape of the corn seed is different from the other seeds. The water is absorbed near the root area of the seed.
  6.  The fern is very different because its seeds are not exactly like the corn and bean seeds. Ferns produce spores on the back of the plant.
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