Plants and Photosynthesis

Plants and Photosynthesis

Look at the bottom of the page. Do you see the two people there? The girl's name is Emma. The boy's name is Alex. They are here to help you understand this book. Emma will read out loud in English. Alex will read out loud in Spanish.

Click on them later in the book when you want them to read.

Think about plants . Trees are plants. Flowers are plants. Grass is a plant. A plant has three main parts. It has a stem . It has roots . It has leaves . Some plants have fruit and vegetables , too.

People eat plants every day. What is the last plant you ate? Did you eat the stem ? Did you eat the roots ? Did you eat the leaves ? Did you eat a fruit or a vegetable ?

People and animals need food to live. What about plants? Do you think plants need food?  

Plants need food, too! Plants, people, and animals are living things . All living things need food. Rocks are not living things. They do not need food. 

Think about how you eat food. You put it in your mouth. You chew the food. You swallow the food. Plants do not have mouths. Plants eat and drink with their roots . Roots take water and minerals from the soil . Plants need water to make energy and minerals to be strong. 

Plants breathe with their leaves . Leaves have holes called stomata . Stomata take in carbon dioxide from the air. Plants breathe out oxygen. People and animals breathe in oxygen. We need plants to live.

In the picture you see CO2 and O2. CO2 means "carbon dioxide." O2 means "oxygen." 

Plants are made up of cells . A cell is the smallest part of a plant. You need a microscope to see cells. 

Plant cells have many parts. The parts work together to make things the plant needs. The cell is like a factory . Each part has a different job. These parts are called organelles .

The cell wall protects the plant cell. The cell wall is strong. Inside the cell wall is the cell membrane . The cell membrane is thin. The job of the cell membrane is to guard what enters and leaves the cell.

Chloroplasts are what make plants green. They turn carbon dioxide , sunlight, and water into sugar. Sugar is energy for the plant.

The mitochondria take the sugar and turns it into energy. If there is only one, it is called a "mitochondrion ."

The nucleus is like the brain of the cell. It tells all of the organelles what to do. 

The cytoplasm is like jelly inside the cell. It holds all of the organelles in place. 

Humans and animals eat plants. They give us the sugar they store as energy . Animals and humans get energy from eating other animals, too.

When living things die their energy does not disappear. Decomposers turn dead animals and plants into food for other plants. The energy moves in a circle, like in this picture.