Plant Parts and Functions

Grade Level

6 - 8

Purpose

In this lesson students will learn about plant parts and how they function in plant growth and reproduction. Grades 6-8

Estimated Time

Two 60-minute sessions

Materials Needed

For teacher demonstration:

Celery or white carnation flowers
Red or blue food coloring
Two glass jars filled with water
Potted plant
Clear plastic bag
Twist tie

For each group:

2-3 different types of leaves
Clear nail polish
Clear tape
Microscope
Elodea leaves
4 slides and coverslips

For each student:

Vocabulary

anther: male part of flower that holds the pollen

carpel: the female reproductive part of a flower

cotyledon: an embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed

dicot: a class of plants that contains two cotyledons

filament: the thin stalk that supports the anther

flower: the part of a plant that contains reproductive parts and attracts pollinators

fruit: the part of a plant that develops from the flower and contains the seeds of the plant

leaf: the flat or needlelike part of a plant where photosynthesis happens

monocot: type of flowering plant that has one cotyledon to store food for the young plant and has leaves with parallel veins and fibrous roots

ovule: plant part that contains embryo

petal: the colored segments of a flower

phloem: a portion of the vascular system in plants, consisting of living cells arranged into tubes that transport sugar and other organic nutrients throughout the plant

pollen: the fine, powder-like material produced by the anthers of flowering plants

root: the part of the plant that grows into the soil to anchor the plant and collect water and nutrients

root hairs: tiny hair-like structures that are on the ends of roots and aid in nutrient and water absorption

seed: the part of a flowering plant that contains an embryo within its protective coat and a stored food supply

sepal: an individual leaf that makes up the calyx of a flower

stamen: the male part of the plant containing the pollen, anther, and filament

stem: the main supportive part of a plant; part of the transport system carrying water from the roots and food produced during photosynthesis to other parts of the plant

stigma: female part of the flower that receives the pollen

xylem: the specialized cells of plants that transport water and nutrients from the roots to the leaves

Background Agricultural Connections

This lesson is part of a series called, Too Much? Too Little? created to introduce middle school students to the connection between soil nutrients and the food they eat. The lessons consist of a series of demonstrations and hands-on experiments that show that plants require nutrients in certain quantities. The lesson series allows students to investigate soil properties, learn how to properly prepare fertilizer nutrient solutions, identify deficiencies in plant nutrients using a key, and much more. Other related lessons include:

Plant Parts and Functions: Anatomy and physiology of a plant.
Digging Into Nutrients: How plants obtain nutrients from the soil.
The Right Solution: How fertilizer solution is properly calculated and applied.
Can We Have Too Much of a Good Thing?: Effects of applying too much or too little fertilizer.
The Right Diet for Your Plants: Read fertilizer labels and choose the best fertilizer.
Let's Vote On It: How soil nutrients effect local communities and economies.
It's a Dirty Job: How earthworms benefit soil.

Plants are vital to life on Earth. Plants are known as producers because they use energy from the sun to make their own food and are the main source of energy entering food chains. Sunlight energy is transferred by plants into chemical energy through the process of photosynthesis. Consumers like deer, humans, and mice eat plants and that energy gets transferred from one organism to another through the food chain.

Plants come in all shapes and sizes and can be found on mountain tops, in valleys, deserts, fresh and salt water—almost everywhere on Earth. Some plants, like the Giant Sequoia tree, are enormous while other plants, like the weeds growing in between sidewalk cracks, are tiny. There are carnivorous plants that trap and digest insects and animals as large as rats. The largest flower in the world, the Corpse Flower, Amorphophallus titanium, is also one of the smelliest. This flower can grow up to 20 feet tall and 16 feet wide, and it attracts flies, which are its pollinators, with an aroma of rotting meat.

Plants provide us with food, clothing, medicine, shelter, and oxygen. Everything we eat comes directly or indirectly from plants. Each part of the plant plays a specific role. Plants hold soil in place with their roots, and roots anchor the plant in the soil and absorb nutrients. Leaves act as food factories by capturing sunlight energy and transforming it into food for the plant through photosynthesis. Flowers are involved in plant reproduction. This lesson provides activities for students to explore the structure and function of plant parts.

Engage

Ask students to brainstorm plants that we eat, or products that came from plants. Students can name any fruit, vegetable, or grain. Make a list on the board in a single column.
Choose some of the food items from the list and ask the students how they were produced. For example, if the students listed an apple, ask them how apples are grown. If they do not know, explain that apples grow on trees and develop from a flower. Explain that a farmer must understand biology to be successful in producing apples. Give other examples reinforcing the fact that understanding basic biology and plant anatomy is crucial to the successful growth of the plants we use for food. Today, students will be learning about the parts and functions of plants.

Explore and Explain

Set up the following class demonstrations to introduce plant parts and functions.
- Bring a potted plant to class and have the class observe the plant. Next, cover one branch and its leaves with a clear plastic bag and make a tight seal around the branch. Ask students to look at the branch, leaves, and plastic bag as soon as it has been attached. Water the plant as needed and observe the bag over the next couple of days. Condensation should develop inside the bag. Ask students to tell you why this is happening. This is an easy way to demonstrate transpiration from the leaves.
- To demonstrate the function of xylem, put cut stalks of celery in clear jars with water. Make a fresh cut at the bottom of the celery stalk prior to adding them to the water. Add red or blue food coloring to one jar. Have students observe the celery over the next day. Ask them why the leaves of one stalk of celery are turning the color of the food coloring. White carnation flowers may also be used for this demonstration.
- Both of these demonstrations lead into the student handout, Plant Parts and Functions. Go over this informational handout together as a class.
Review Plant Parts and Functions Lab.
- Lead students in a demonstration of set up for the "Stomata Observation" activity and facilitate a discussion of the questions to be answered in the activity.
- Lead students in a demonstration of set up for the Chloroplast Observation activity and facilitate a discussion of the questions to be answered in the activity.
After students have completed the Stomata and Chloroplast Observations, have a class discussion about what students observed. Draw labeled diagrams on the board to reinforce specific plant structures and functions.
As a conclusion to your discussion, ask students the following riddles about plants they eat.
- My taproot gathers nutrients from the surrounding soil. I am orange and I have feathery green leaves with veins in a netted pattern. Rabbits and people like to eat me.
  - What am I? carrot
  - What plant part am I? root
- I transport water, nutrients, and food the plant makes for itself. I have tubes that act as roadways for water, nutrients, and the food I make. I have green shoots which are harvested after about 2 years when they are about 9" tall. I am often steamed or boiled for a healthy side dish.
  - What am I? asparagus
  - What plant part am I? stem
- I attract insects so that I can become pollinated and produce seeds. I am white and a member of the cabbage family. Some people say I look like clouds.
  - What am I? cauliflower
  - What part of the plant am I? flower
- I have lots of iron. I use sunlight, carbon dioxide, nutrients, and water to make food for myself and the rest of my plant parts. I go well with salads. Popeye is a big fan.
  - What am I? spinach
  - What plant part am I? leaf
- If planted and the conditions are right, I will grow into a tree. I have a light tan shell that easily splits in two and greenish colored nut. I grow on trees and have become a popular nut to grow in California. I start with a “P.”
  - What am I? pistachio
  - What plant part am I? seed
- I am the yellowish-orange fleshy substance around a large seed. I protect the seed and encourage insects or larger animals to eat me so that my seeds can be dispersed. I have fuzzy skin.
  - What am I? peach
  - What plant part am I? fruit

Variations

Have students draw their own plant, label the parts, and describe the functions of each plant part.
Begin the lesson by making a KWL chart with your class. Have students copy the chart onto a piece of notebook paper. Conclude with a class exercise to complete the chart, filling in any of the blank spaces that were not filled in at the beginning of the lesson.

ELL Adaptations

This lesson incorporates hands-on activities. Kinesthetic learning events provide an excellent learning environment for English language learners.
Demonstrate all lab procedures to the class before they begin the lab.
Add new vocabulary to a word wall and match photos to the new words.

Elaborate

Divide students into groups and assign each group to be experts on one plant part and function. Groups should research their plant part and make a short presentation with a slideshow presentation or poster board to provide the class with in-depth information about their assigned plant part. The group should also bring in several different examples of that plant part from different plants.
Carefully dissect and observe various plant parts. Pull weeds and observe root systems. Observe a celery stock and learn about stems. Cut an apple in half and observe the fruit anatomy. Dissect a roasted peanut or soaked lima bean.
Make an edible plant part salad. Discuss which of the parts the class is eating and the function of each part.

Evaluate

After conducting these activities, review and summarize the following key concepts:

Farmers must have use their knowledge of biology to be successful in growing crops that provide our food.
Plants provide food for humans in the form of vegetables, fruits, and grains.
Plants also provide feed for animals such as grains and forages. In turn, these animals provide food for humans such as milk, meat, and eggs.

Sources

Acknowledgements

This lesson was updated in 2013 with funding from California Foundation for Agriculture in the Classroom and a grant from the California Department of Food and Agriculture’s Fertilizer Research and Education Program. The Fertilizer Research and Education Program (FREP) funds and facilitates research to advance the environmentally safe and agronomically sound use and handling of fertilizer materials. FREP serves growers, agricultural supply and service professionals, extension personnel, public agencies, consultants, and other interested parties. FREP is a part of the California Department of Food and Agriculture (CDFA), Division of Inspections Services.

Editor: Shaney Emerson
Executive Director: Judy Culbertson
Illustrator: Toni Smith
Layout and Design: Nina Danner
Copy Editor: Leah Rosasco