|Life Science||Diversity And Adaptations Of Organisms 7H2.00||Process Of Science||Explaining 1.5 c|
CONTENT STANDARDS: Life Science
CONTENT TOPIC: Diversity and Adaptations of Organisms
CONCEPT: Plants are classified according to various structures.
CONTENT OBJECTIVE: 7H2.00 To understand the broad taxonomic division of the plant kingdom
INSTRUCTIONAL OBJECTIVES: The learner will:
TN COMPONENT OF SCIENCE: Process Of Science
BENCHMARK: Prior knowledge provides a foundation for new learning experiences.
There are two main groups of plants, non-vascular and vascular. Non-vascular plants lack true roots, stems and leaves. They must depend on osmosis and diffusion to move materials in and out of their structures. Due to the pull of gravity, these non-vascular plants do not grow tall. Vascular plants have advanced enough to develop true roots, stems and leaves. These plants have weed-developed tubes that will transport materials up and down their structures. Therefore, these plants can and do grow tall.
The simple plants that are non-vascular are algae, moss and liverworts. The different types of algae are given credit for many things man enjoys - the greatest contribution being the huge amount of oxygen that algae contribute to our environment through photosynthesis. One of the best types of algae to observe under the microscope is the spirogyra. (Perform laboratory activity and point out the large, winding chloroplast.)
Mosses and liverworts are also non-vascular plants. They have no true roots, stems or leaves so diffusion and osmosis move materials through these very "low to the ground" plants. They have structures that look like these plant parts but are not true vascular structures. (Look at moss under a microscope.)
The first class of vascular plants involves plants known as ferns. These plants have true roots, leaves and stems. This situation allows ferns to grow tall because they can transport materials up and down the plants. These plants, class Flicinae, were once the dominant plants on earth and were found in vast "fern forests". Ferns do not reproduce with seeds as do the higher plants but they reproduce with spores. These spores are located on the underside of fronds, the fern's leaf. (Have this under magnification or observation.) The ferns are not nearly as plentiful as a natural plant today. Due to vast changes in the earth's atmosphere, natural ferns are found mainly in the tropical climates or in dense forests.
There are two groups of seed plants on earth, the gymnosperms and the angiosperms.
Gymnosperms are the plants that are known as evergreens. They keep their leaves or "needles" all year. They are also known as conifers. The seeds of the gymnosperms are produced in a cone. The seeds are released from the cone when mature. This is why the seeds are referred to as "naked seeds". They are not protected once they are released from the cone. Some of the more common plants in this group are pines, cypress, firs and boxwoods.
The most advanced plants on earth are the angiosperms. These are the flowering plants that produce seeds in a fruit. The angiosperms are deciduous because they lose their leaves each fall. The reproductive structure for angiosperms is the flower. Once the eggs inside the flower are fertilized the seeds develop. A fleshy fruit develops around the seeds to act as a protector for the seeds. This fruit can also aid the seeds in dispersal away from the parent plant.
2. How is the transport system in vascular plants similar to the human circulatory system? (Move liquids)
1. Exhibit a fern frond under microscope - face down to show spores on underside of frond.
2. Have students collect and bring pine cones - look for seeds or places where seeds were in the cones.
3. Obtain flowers from local sources (florist, grocery, nursery...) to observe under microscope. Also, cut open types of fruits to show the seed or seeds in the fruit or vegetables.)
cone - structure containing seeds
deciduous - plants that shed leaves in the fall
diffusion - movement of materials from high to low concentration - a natural movement
fertilize - egg & sperm
osmosis - water moving through a membrane
photosynthesis - process where plants make food
sessile - non-moving, stays in one place
spirogyra - type of green algae
spores - reproductive cells of ferns
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