|Life Science||Diversity And Adaptations Of Organisms 7H3.00||Process of Science||Observing 1.1 a|
CONTENT STANDARD: Life Science
CONTENT TOPIC: Diversity And Adaptations Of Organisms
CONCEPT: Plants are classified according to various structures.
CONTENT OBJECTIVE: 7H3.00 To understand the development of plants and their systems
INSTRUCTIONAL OBJECTIVES: The learner will:
TN COMPONENT OF SCIENCE: Process of Science
BENCHMARK:By incorporating prior knowledge with the process of observation, a better understanding of one's environment may develop.
1. Place a stalk of celery in a beaker of colored water. Observe the xylem tubes in the celery as the colored water moves through the celery
2. Have students draw, label and color the parts of a plant. These should be displayed in the classroom or hall .
3. Each student brings an example of a herbaceous or woody stem to show and explain.
4. Observe classroom plants and the phototropism toward a light source (Place in a window, if possible)
The purposes of roots include:
1. Anchor plant in ground
2. Absorb, store and transport water and minerals for the plant
3. Grow downward due to the pull of gravity
The first root to develop on a plant is the primary root. Any root branching from this first root is called a secondary root. The microscopic roots that actually do the diffusion and osmosis of material are the root hairs.
Xylem cells make up the tissues called xylem tubes. These vascular tubes conduct water and minerals up the plant from the ground here the water and minerals are taken in. Phloem cells make up phloem tubes which bring substances down through the plant (example- glucose made in leaves travels down to other plant parts through phloem)
(Do the activity using celery and colored water. Have students observe the different types of roots.)
The stem is another very important part of the plant. Some of the purposes of stems are as follows:
1. Support leaves and hold them up toward the light (ask-why? The stem allows the maximum exposure of the leaves to light.)
2. Some stems can produce food (example - broccoli, celery . . .)
3. Stems move water, food, minerals up and down the plant
4. Some store food
There are two types of stems, herbaceous and woody. The herbaceous stem are soft, green in color and flexible. The herbaceous stems are usually found on plants that live only one year. Examples would be the stems of a tomato plant. (Show example-most house plants have herbaceous stems.)
The woody stem is a hard stem that is dry on the outside. This type of stem is designed to last several years and to withstand extreme changes in temperature. (Show woody stems such as small branches and twigs from trees or shrubs)
There are some stems that are very different. Most of us are not aware that these unusual structures are actually stems. The potato tuber is an underground stem that stores a great amount of food . (show potato) Another underground stem is the rhizome of Bermuda grass and Johnson grass. Ask students if they have ever had to pull grass from flower beds or crop fields.)
The leaf is defined as the "food factory" of the plants. This is where most of the photosynthesis occurs in the plants. (Have students draw and label the cross-section of a leaf.)
The layers you drew and labeled as palisade layer and spongy layer are the two layers that contain chlorophyll. Chlorophyll is the green pigment in plant that is involved in the process of photosynthesis. The tiny openings of labeled stomata are the openings where gases enter (H20, O2, C02) and leave (H20, O2) the plant.
The process of photosynthesis is a very complex chemical process. We are going to draw and learn a simplified version. You will be able to trace the sunlight which is trapped in the glucose molecule. You will understand how carbon dioxide is used and how oxygen is produced. Have the students draw the process.)
The chemical formula for photosynthesis is:
6C02 + 6H20--------light/chlorophyll--> C6H1206 + 6O2 + 6H20
The plant needs light, warm- temperature, C02, water, minerals, and chlorophyll. The high energy glucose that is produced is used by plants and animals as the energy source to sustain life. The oxygen produced and given off as a waste product is used by animals and other life structures.
PHOTOSYNTHESIS AND RESPIRATION
Purpose to produce glucose to release energy
Needed C02, H20, C6H1206, O2
Waste O2, CO2
When Daylight 24 hrs a day
Plant behavior is very different from the behavior exhibited by consuming animals. Plant behavior is known as tropism. These tropism are a plants response to a stimulus in the environment. One of the most widely known tropism in plants is the phototropism - a plant's response to light. The plant will turn it's leaves toward the light . (Show classroom plants.) Other common tropism observed in plants are hydrotropism - growth toward water, and geotropism - growth with or against gravity.
Plants do not have sense organs, muscular systems or nervous systems. Tropism are controlled by plant hormones called auxins.
KEY QUESTIONS (CHALLENGE QUESTIONS):
1. Can you plant a seed upside down? (No) Why not? (Gravity)
2. What part of your circulatory system is similar to a plants root hairs? (Capillaries)
3. Why are leaves arranged around a stem instead of in a line up and down the stem? (So each leaf can receive light and not be shaded by other leaves.)
4. Why is chlorophyll called an enzyme? (It speeds up the chemical changes occurring in photosynthesis.)
diffusion - movement of materials from an area of high concentration to an area of low concentration
flexible - soft, elastic
herbaceous - stems that are soft and green
osmosis - movement of water through a membrane
palisade layer - layer of cells in a leaf that contain chlorophyll
phloem - tubes that carry food made by plant
primary root - first root to develop from a seed
rhizome - underground stem
root hair - microscopic roots that undergo diffusion and osmosis with materials
secondary roots - roots branching from primary roots
spongy layer - layer of cells containing chlorophyll
stomata - openings on underside of leaves
tropism - responses made by plants
tuber - underground stem
woody - stems that are hard and dry
xylem - tubes that carry water and minerals
This is the time this file has been accessed since 04/02/98.
The University of Tennessee at Martin is not responsible for the information or views expressed here.
Seventh Grade Science Home Page