From Seeds to Plants and Beyond
Debra Leiter-Weldy
Carpinteria Middle School
Carpinteria Unified School District
Description:
Debra’s 7th grade science team is creating a plant unit where students will gain a complete understanding of photosynthesis, seeds, seed dispersal, roots/stems/leaves, and plant reproduction through labs and activities both in the classroom and in the school garden. We need soil, fertilizer, seeds, and a new irrigation system in the garden to make it a functional learning environment for all our 7th grade students.
Project outcome:
1.Students will gain an interest in learning about plants by understanding thesimilarities in survival needs among all living things.
2. Students will be able to sort, classify, and graph by manipulating different kinds of seeds
3. Students will be able to identify and label the basic parts of a plant, including: root, stem, leaves, flower, and petals, by creating their own flower and explaining it to the teacher or their classmates.
4. Students will understand that plants have various parts and functions
5. Students will learn about photosynthesis.
6. Students will use inquiry based learning both in the classroom and in the garden.
Target student grade level:7th Grade Life Science students; students include general education, ELL, and special education students
Time required:Approximately 2 week unit plus continuous upkeep of the garden.
CA Content or Common Core State Standards addressed with this project:
1.Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.
2. Developing and Using Models
3. Constructing Explanations and Designing Solutions
4. Construct a scientific explanation based on valid and reliable evidence obtained from sources
5. Engineering Design
Assessment,Materials,Lesson Plans:
HOW DOES PHOTOSYNTHESIS WORK?
Very few plants can actually trap their own food and none can go grocery shopping so plants need to make their food by themselves if they want to eat! Plants are fortunate as they are the only living organisms that can make their own food. How do they do this?
They make their food by combining carbon dioxide gas that is found in air with water and nutrients that they absorb from the soil.
In order to do this though they need energy – which they get from sunlight. The energy from sunlight (solar energy) is used by the plant to make carbon dioxide and water react chemically together and change into glucose (food) and oxygen. This process is called photosynthesis. The word photosynthesis comes from two Greek words: photo meaning light and synthesis meaning putting together so photosynthesis means “putting together with light”.
We can write photosynthesis like this:
Carbon Dioxide(gas) + Water => sunlight => Glucose + Oxygen(gas)
6 CO2 + 12 H2O —-sunlight——> C6 H12 O6 + 6 H2O + 6 O2
In the process of photosynthesis plants change solar energy into chemical energy.
What has the sun got to do with photosynthesis?
The sun is a very powerful source of energy. People are always trying to harness it to make electricity, warm their houses, heat their water etc. Plants figured out how to use solar energy millions of years ago to make their food. They use the light energy from the sun (solar energy) and convert it into chemical energy that is stored as sugar (glucose) in the plant. Excess glucose is stored as starch in the leaves, roots, stems and seeds of the plant. The energy from the sun is transferred to the plants. This energy is then passed to animals when they eat plants. Whenever the plant needs energy it breaks down its stored glucose for its life processes
How do plants capture the sun’s energy?
Plants can do this because of leaf structures called chloroplasts that contain a special substance called chlorophyll.
Chlorophyll is the pigment in plants that gives leaves their green color. This pigment that is found in the leaves and the stem of the plant is responsible for absorbing light energy from the sun. At night when there is no light a plant stops making food.
Why are most leaves broad and flat?
It shouldn’t be too surprising for you to learn that the plant’s structure is very well adapted to trap sunlight and absorb carbon dioxide. A wide broad surface will capture far more light than a thin narrow leave surface. Solar panels that you see on houses are also broad and flat for the same reason.
Why is photosynthesis so important?
Photosynthesis is one of the most important chemical reactions in the world. What are the reasons for this?
Photosynthesis makes food for plants and for animals.
We have already learned that plants feed themselves by using sunlight to convert carbon dioxide and water into food (sugar). Whenever the plant needs energy for itself it breaks down its stored food. Animals get their food by eating the plants so they depend on plants for their food.
Photosynthesis results in oxygen gas being made that is released by the plant into the atmosphere for living things to breathe.
Living things breathe in oxygen and breathe out carbon dioxide all the time. Fortunately plants do the opposite. When plants are making food they breathe in carbon dioxide and breathe out oxygen. Therefore plants are extremely important to humans and animals as they give them oxygen to breathe and prevent us all from suffocating. Oxygen is needed by all living organisms to burn up food for energy.
Photosynthesis results in carbon dioxide gas being removed from the atmosphere. Carbon dioxide is a greenhouse gas that is responsible for global warming.
Questions
1. What is a simple, one sentence explanation for photosynthesis?
Photosynthesis is ______
1. Explain what this formula (equation) means:
Carbon Dioxide(gas) + Water => sunlight => Glucose + Oxygen(gas)
(Hint – The picture with the happy face flower will help.)
This formula shows how______
______
2. What are the functions (jobs) of chlorophyll and chloroplasts in plants? (Hint: Use the picture with the happy face sun and the descriptions to help you.)
Chlorophyll is ______
______
Chloroplasts are ______
3. Read the last section called, “Why is Photosynthesis so Important?”.
One of the problems of global warming is that humans are creating too much carbon dioxide from polluting the atmosphere. How can plants help?
Plants can help reduce global warming by ______
______
How Plants Spread Their Seeds
Before they can grow into new plants, seeds need to leave the seedpod. If all the seeds a plant produced landed just underneath the parent plant, they would be too crowded, and the established large plant might not leave them enough light or water for them all to develop properly. When you plant seeds too thickly in a pot, you can see that they grow tall and leggy, and each plant is weak and spindly. The various methods of seed dispersal are designed to ensure that as many seeds as possible have a good chance of growing up to produce seeds of their own.
Sometimes, the pod or fruit containing the seeds is carried away from the parent plant; sometimes, individual seeds are spread to a new location. The size and shape of the seedpod or the seeds influences how they are dispersed. The main methods plants use to disperse their seeds to places with better growing conditions than directly under the parent plant include gravity, animals, force, wind and water. Often, a plant will spread its seeds by a combination of these methods. For instance, a fruit falling to the ground by gravity might then be carried away by animals, or a seed blown by the wind might land in water and be transported somewhere else before germinating.
Gravity: ex. apples
If they have a tough outer shell, they may roll some distance from the parent plant. The higher up the tree they are, and the larger they are, the further they can roll.
If they have a soft skin, they may break open when they hit the ground and the individual seeds may be scattered.
When they reach the ground, some seeds are taken further from the parent plant by animals or water.
Animals: ex. Animals
Animals of all sorts and sizes help plants to disperse their seeds. The method they use depends on the type of seed.
In the deserts of North Africa, elephants eat the fruits that have fallen from the trees and deposit the seeds in their droppings (poop) several miles away. In South American jungles, monkeys eat figs and other fruit, carrying some away in their stomachs and dropping others onto the ground. In Britain, foxes eat raspberries, squirrels eat nuts, blackbirds eat our strawberries, mice eat grass seeds, and in South Africa, even ants carry seeds into their nests, eat the tasty outer covering and leave the seeds to grow safely underground.
As well as eating them, some animals collect the fruits or seeds and bury them to eat later, but forget about them and the seeds germinate in their new location. Sometimes, as in the case of Mistletoe, the seeds are covered in a sticky slime, which the birds rub off on a new tree. Even humans carry seeds far away for plants - by taking an apple on a picnic, for example, and throwing the core, with its seeds, into the bushes.
Many plants produce fruits or individual seeds covered in hooks or spines, which attach the seed to the animals' fur or feathers - or, in the case of humans, to our clothes or bags. The seeds are then carried a sufficient distance from the parent plant to give them space to grow. Eventually, the seed may fall off, or be rubbed off by the animal.
Force: ex. geraniums
Some plants eject the seeds from the pod by force. There are several methods plants use to fling their seeds out of the seedpod. All of them rely on the effect of evaporation of water in the seedpod, so this method of seed dispersal usually takes place in the sun. If you walk over heathland near Gorse bushes on a hot sunny day, you can hear the explosions of the seedpods as they burst open and send their seeds out. Geraniums also use the heat of the sun to shoot their seeds from the pods. When the seeds are ripe, the seed covers split apart, and the seeds are catapulted out at high speed.
Wind: ex. Dandelions
Wind is one of the main agencies of seed dispersal. The way it transports them depends on the type of seed and where it grows.
Seeds that are almost weightless enable them to be carried long distances by the slightest breeze are familiar all over the world.
Water: ex. coconuts
Some plants make use of water to disperse their seeds. Plants that grow beside or in water often rely on water to transport their seeds for them.
Name______
Per. ______Date______
LIGHT AND PHOTOSYNTHESIS
BRAINSTORM WITH YOUR PARTNERS.
What do you know about sunlight? List words and any concepts you know about light.
How does sunlight travel?
Waves = ______= ______
Each wave has its own ______
The Electromagnetic Spectrum
least energy most energy
______
We only see ______.
Which is made of the colors ROYGBIV
Light travels at ______miles per second
VISIBLE LIGHT: ROYGBIV
Red (______wavelength: Violet (______wavelength
______energy) ______energy)
Light travels in a straight line until it
When light hits something it is either ______, ______
or ______depending on how the particles in an object ______with the light.
1. Absorbs : Energy is converted into ______in an object it hits.
2. Reflects: Light is ______off an object.
3. Transmits: Light travels______an object and ______.
The Colors you see in objects depends on the wavelengths present in the object and how it reacts to ROYGBIV in sunlight.
Ex. Red T-shirt Sunlight hits a red shirt. What happens?
So, what happens with a black t-shirt?
What happens in a white T-shirt?
______
Now let’s talk about…. PHOTOSYNTHESIS and Plants
Objectives: You will be able to explain and draw the process of photosynthesis
You will be able to describe and identify what is needed for photosynthesis to occur and what
are the end products of photosynthesis.
Activity #1: Concept Map
Materials:
Poster paper
Post-Its
Pen/pencil
Brain cells
Directions:
1. Write down as many words or concepts you know about PLANTS on Post-Its
2. Place your Post-Its on the poster paper and draw lines to show relationships. You should write on the lines explaining the relationships.
3. Present your poster to the class.
4. Add or make changes to your poster after all groups have presented.
Reflection:
1. Before this activity, what did you know about plants?
Before this activity, I knew that______
2. What did you learn about plants from today’s activity?
I learned that ______
3. What were some misconceptions (incorrect ideas) that you had about plants?
I was incorrect when I thought that plants ______
Activity #2: Your Tree
1. Read the article, “A Tree is Like a Hungry Kid”.
Answer the questions at the end of the article.
Show your completed work to your teacher.
2. Read the article, “How Does Photosynthesis Work?”
Answer the questions at the end of the article.
Show your completed work to your teacher.
3. Assessment:
Obtain poster paper and a printed list of Photosynthesis terms from your teacher.
Draw a large tree or plant or flower.
Use all the terms on the sheet to label around the tree. Use arrows.
Draw illustrations next to each term
Write the formula for photosynthesis at the bottom of the sheet.
Name______
Date______Per.______
Activity 3: No Sunshine?
Question: What would happen if leaves on a plant were unable to receive sunlight?
Background information: What do you know about plants and sunlight?
Hypothesis:
What do you think will happen to the leaves on a plant when they are deprived of sunlight?
I think the covered leaves ______
Will the other uncovered leaves on the plant survive?
I think the uncovered leaves ______
Will the uncovered leaves help keep the covered ones alive?
I think the uncovered leaves can/cannot______
Experiment:
Materials
Specific leaves in the garden
Aluminum foil
Labels for your leaves
Data table
Procedure:
1. You and your partners will choose a plant in the garden to use for this experiment.
2. Draw what your leaves look like before you begin. This is your CONTROL.
3. Cover 2 of the same leaves from your plant and lable them with masking tape:
Period______; Student names.
4. Check the leaves daily for 5 days.
5. Determine the effects on the leaves.
Data Table 1
Draw a detailed picture of your leaf.
Describe color, texture, smell.
Data Table 2
Day / Foil covered leafIllustration / Foil covered leaf
Description / Control Leaf
(no foil)
Illustration / Control Leaf
(no foil)
Description
1
2
3
4
5
Reflection
Look back at your hypotheses and what you thought would happen:
•What do you think will happen to the leaves on a plant when they are deprived of sunlight?
•Will the other uncovered leaves on the plant survive?
•Will the uncovered leaves help keep the covered ones alive?
Discuss what happened in the experiment and whether your hypotheses were correct or incorrect.
In this experiment I thought that ______
______
What really happened was that ______
______
I was surprised that ______
CO2/ H2O
/ C6H12O6
(sugar)
O2
/ / Soil
(nutrients)
Sunlight
/ Leaf
/ Plant
Photo-synthesis / Chlorophyll / Oxygen
]Name______Date______Period______
Plant Assessment
On the piece of paper given to you:
1. Draw a large tree or plant or flower.
2. Use all the terms on this page to illustrate and label around your picture.
3. Use arrows
4. Describe or define each term.
5. Write the formula for photosynthesis at the bottom of your picture.
6. You can use your notes or the book.
Terms:
Roots
Soil
Minerals
Leaves
Root cap
Root hairs
Phloem
Xylem
Water (H20)
Carbon dioxide (CO2))
Sugar (C6H12O6)
Sunlight
Oxygen
Stem
Branch
Flower
Name______
Date______Per.______
Plant Plumbing
Objective: Students will learn how water flows through a plant.
Question: What happens when broccoli and celery are placed in colored water?
Background Information:
Read this.
Write the underlined vocabulary words below.
Work with your partners to figure out the meaning of the words by re-reading the information around them.
Imagine carrying 100 buckets of water to the top of a 10-story building. This is hard work for humans, but trees do it every day! Trees and other plants take water in through their roots, pull it up through their stems, and finally transpire it into the air through their leaves. Just as you suck water up through a straw, transpiration sucks water up through plants and out into the air through tiny holes in leaves called stomata. This flow of water is essential for plants, since water is involved in practically everything plants do.