The plant life cycle begins with a seed. The seed will sprout and produce a tiny, immature plant called a seedling. The seedling will grow to adulthood and form a mature plant. The mature plant will reproduce by forming new seeds which will begin the next life cycle.
As described above this life cycle is generally used by the flowering plants. The flowering plants include trees, grasses, shrubs, and, of course, flowers. There are also lower types of plants including ferns and mosses. These also have a life cycle but they do not produce seeds. They produce a different type of reproductive cells called spores.
In the flowering plants, there are male and female structures inside the flower. These produce the seeds. A more detailed explanation and examination of seeds is found in the Bean Plant Activities section.
It is instructive to examine flowers and seeds of various plants in order to study and learn their similarities and differences. It is also necessary to study ferns and mosses and compare them with the flowering plants.
1. Students brainstorm in class about what plants are included in the term flowering plants. Their suggestions and discussions are written on the board and in their Science Journals. They learn that in addition to common flowers, the flowering plants include trees, shrubs and grass plants.
2. Students examine pictures of flowers. Flowers have various parts which can be studied. An example is shown below.
They learn the different parts by completing a definition table as suggested below.
|Flower Part||What the flower part does|
|Stamen||The stamen is the male part of the flower. It produces pollen which fertilizes the immature seeds.|
|Pistil||The pistil is the female part of the flower. It contains the immature seeds. After the immature seeds are fertilized they become the seeds which produce the next cycle of plants.|
|Petal||Many flowers have petals which have bright colors to attract insects. The insects carry pollen which fertilizes the immature seeds.|
|Sepal||The sepals appear like small green leaves. They are protective structures used when the flower is not completely developed in the bud stage.|
|Receptacle||The receptacle supports the flower on the end of the stalk.|
3. Students note differences between different types of flowers.
4. It this study is done in the early spring, it is possible to see the trees flowering. Of course, anyone with allergies can tell that the trees are flowering without looking. Trees nearby will appear to have a reddish glow around them caused by the flowers. The flowers can be seen on trees with low-hanging branches.
1. Students write about the similarities of the various flowers they studied. They make the table of the parts and see where the parts are located in the flowers.
2. Students write about the differences of the various flowers they studied. They collect drawings or photographs of different flowers to show the ways in which they are different.
1. Students study mosses to see the ways in which they are different from the flowering plants.
2. Students study ferns to see the ways in which they are different from the flowering plants.