Chapter 2

Energy From Plants

Lesson 1- What are plants’ characteristics?

• Plants are made of small building blocks called cells.

• Different parts of a cell do different jobs.

• Plants are multi-celled organisms made up of tissue and organs.

How plants make food• Plants need

sunlight and water in order to live, grow, and reproduce.

• They also need carbon dioxide from the air and mineral nutrients from the ground.

photosynthesis• Unlike animals, plants

make their own food.

• The food they make is sugar or glucose.

• The process of making sugar is called photosynthesis.

Photosynthesis• In photosynthesis,

plants use carbon dioxide that their leaves absorb from the air and water that their roots absorb from the soil.

*The tubes in the stem carry sugar to other parts of the plant.

storing glucose• Three parts of the

plant store the sugar for the plant.– Stems– Roots– Leaves

Chloroplast• Photosynthesis

takes place in the chloroplasts of leaf cells.

• Chloroplasts contain chlorophyll.

Chlorophyll is the

substance that makes

plants green

Sing this song!!If you want to know How a plant grows.

It takes water, air, and sunlightAnd makes cellulose

Every plant can do this Fundamental process And we can call this

Photosynthesis

Unlike me and you Plants need CO2

And they make oxygen That stops us turning blue

CHORUS

It’s a miracle How all the chlorophyll

Captures sunlight in the leaves

Of the plants and the treesA plant of any size

Can do it if it tries But we’re not green,

so we can’t photosynthesize

CHORUS

It’s a miracle How all the chlorophyll

Captures sunlight in the leaves Of the plants and the trees

CHORUS

Every plant can do this Fundamental process And we can call this pho-to-syn-the-sis

Photosynthesis

Lesson 2- What are the parts of plants?

• A plant has different parts. Each part plays an important role in helping the plant survive.

• Most plants have three organs, whether they are a redwood tree or a dandelion. – leaves– stems– roots

leaves• All leaves have the same role.• Their job is to produce food so the plant

can survive in its environment.• Leaves may be different shapes and sizes

but they all produce food for the plant.

stems• What does a tree trunk

have in common with the thin stalk of a dandelion?

• They are both stems and they have two basic functions.– They carry water, minerals,

and food between the roots and leaves.

– They support the plant, holding the leaves up so they can get sunlight.

roots• The two main jobs of roots are:– to anchor the plant firmly into the

ground.– take in water and mineral nutrients from

the ground around them.

Roots do not contain chlorophyll

Roots grow away from the stem in search of water and nutrients.

roots• Plants can either have taproots or

fibrous roots.Most trees and grasses have fibrous roots. In this kind of root system, the roots spread out in many different directions.

In taproot systems, there is one main large root that grows straight down.

Lesson 3- How do plants reproduce?

• Scientists classify plants by how they reproduce (make new plants)

• Flowering plants use parts of the plants to reproduce.

• There are four main parts to a flowering plant.– Petals– Sepals– Pistil– Stamens

Parts of a flower

The petals are the parts of the flower that are colorful.

The sepals are the green leaves below the petals. They cover the bud.

The pistil is the female part of the plant.

The stamen is the male part of the plant. They are the smaller stalks around the pistil

Anthers are the top of the stamen

Reproduction• Stamens produce the sperm cells.• The pistil produces the flowers egg

cells.• They combine to make seeds.

Fertilization• In order for a seed to

form, pollen has to get from a stamen to a pistil.

• The movement of pollen from the stamen to the pistil is called pollination.

• The process of sperm cells and egg cells combining is a process called fertilization.

• After they fertilize, the egg grows into a seed and the ovary becomes a fruit.

Animals play a huge part in the process of pollination.

Lesson 4- What is the life cycle of a plant?

• A seed needs the right conditions to begin growing. – It needs 3 things.• Right amounts of

oxygen• Water• Right temperature

Seeds on the moveAnimals help scatter seeds.

-Animals eat the fruit on the plant and digest the seeds…the animals eventually leaves droppings on the ground with seeds in them.- Seeds can catch on animal fur.- Some animals bury nuts for the winter and they end up growing into plants.

Wind as a helperWind can also help

spread seeds. Have you ever seen a dandelion puff blow in the wind?

Some plants have “parachutes” that carry seeds in the wind.

Milkweed plants and cottonwood trees also have “parachutes” that carry fruits and seeds in the breeze.

Some fruits and seeds can even be spread by floating on water!

Starting to grow• If a seed does not have what it needs

to start growing, it remains dormant (a state of rest).

• Some plants don’t need seeds to grow. These plants don’t make flowers or cones. – These plants grow from spores, not

seeds.• A spore is a tiny microscopic cell.

Spore Reproduction• There is a two-step cycle in

the reproduction of spores.– The plant produces a spore– A male and female spore

combine and grow into a plant

• Not all plants grow from seeds or spores. Some grow from stems, roots, or leaves.

• Some plants, like strawberries, grow from stems called runners.