How Plants Grow

In this lesson, students build on their understanding of living things by focusing on plants. They discuss what plants need to survive and how plants grow from a seed to an adult plant. Students dissect a seed to explore how seeds can turn into plants and then compare the growth of seeds in different conditions.  

• Plants are living things because they need food, air, and water, and they have different parts that help them get what they need to survive. 
• Many plants begin as a seed, which is a young plant inside a protective coat.
  
  

• Why do plants need food? How do plants get food?
• What part of the plant collects sunlight?
• How do plants get the air they need to survive?
• Why do plants need water? How do plants get water?
• How does food get from the leaves to the rest of the plant, and how do water and minerals get from the roots to the rest of the plant?
• How can the seed begin to grow underground, even though there is no light there?  
• What do seeds need to grow?
  
  

Misconception: Plants are not alive because they don’t move.

Fact: Plants are alive, and they need air, water, and sunlight to survive.

Misconception: Plants need sunlight to stay warm.

Fact: Unlike animals, plants need sunlight because they make their own food from sunlight through photosynthesis.

Misconception: Plants get water from their leaves.

Fact: Plants take in water through their roots.

Flower:  the part of the plant that makes seeds

Leaf: the part of the plant that takes in sunlight and makes food

Pollen: a fine powder that flowers make

Pollination: the way some plants make new seeds

Roots: the parts of a plant that grow under the ground; hold the plant in place; take in nutrients and water from the soil

Seed:  a young plant inside a protective coat

Stem: the part of a plant that holds the leaves and flowers in place; water and nutrients travel through the stem to the rest of the plant

Plants and the Sun

Greenhouses are transparent so the sun can shine through. Plants need sunlight. Leaves are parts of plants that take in sunlight and make food.

Food gives plants energy. This helps them grow. Plants also need air to grow. Plants take in carbon dioxide from the air with their leaves. They release oxygen back into the air.

Plants and Water

Plants also need water to grow. Becky waters her plants in the greenhouse. Plants take in water with their roots. Roots grow under the soil. Roots also take in minerals from the soil. Plants use minerals to build their body.

How a Plant Grows

Most plants begin as a seed. A seed is a young plant inside a coat. The coat protects the seed. The seed stores food. The seed needs air and water.

Plants need a certain temperature to grow. It cannot be too hot or too cold. With the right temperature, air, and water, the seed will begin to grow.

In this lesson, students will conduct an experiment and an investigation. In the experiment, students test whether plants need both water and light to grow by collecting and analyzing data on the height each of the plants grows over 10-15 days. Students then create a scientific diagram of their experiment-in-progress. In the investigation, students dissect a seed. Students use their observations from the seed dissection to help them construct an explanation about how plants change as they grow.