Vocabulary Rating Sheet for Colonial Times: Week 4

HOMEWORK

Plants get energy from a process called photosynthesis. While we get energy from the food we eat, plants make their own! Without photosynthesis, we wouldn’t be able to eat fruits and vegetables; make clothes and other products out of cotton; or obtain many of the medicines we need. Photosynthesis also causes plants to release oxygen, which people need to breathe! In fact, there probably wouldn’t be any animal life on Earth if plants did not engage in photosynthesis. Plants form the basis of the food chain, and if they didn’t grow, there’d be no food for anyone or anything!

What is photosynthesis?

Photosynthesis is the process by which green plants and certain other organisms create energy. Plants collect energy from sunlight and use this energy to make a sugar called glucose. Glucose is the main source of nutrition for plants, fueling their cells for function and growth.

In addition, plants use their roots to drink up water from the soil, and that water travels from the roots to the plant's leaves. Meanwhile, leaves absorb carbon dioxide from the air, and the water and carbon dioxide spread through the leaves into cells called the palisade and spongy cells. These cells contain structures called chloroplasts, which are filled with a green pigment called chlorophyll–it’s chlorophyll that gives plants their green color.

In photosynthesis, chlorophyll traps energy from sunlight, storing it as chemical energy. The process splits water molecules into hydrogen and oxygen atoms, and chemical energy is used to create glucose from the hydrogen and carbon dioxide. The glucose dissolves into extra water molecules and gives the plant plenty of food for growth.

Most forms of photosynthesis release oxygen as a byproduct. So, in a way, plants breathe in carbon dioxide and breathe out oxygen! Since we do the opposite, the cycle goes back and forth in the air!

Answer in your notebook not on this sheet:

1. List three things that a plant needs from the environment to make its own energy:
2. What green substance inside the plant makes photosynthesis possible?

3. List three things that a plant gives off after it has made its own energy:

4. What could you do to a plant to kill it? Base your answer on what we learned about what plants need to live and use at least three complete sentences.

5. Plants put sunlight together with air and water to make food in a process called:

1. ______is a green chemical that catches the sun’s energy and combines it with water, carbon dioxide, and nutrients from the soil to make food for plants.
2. The process of photosynthesis takes energy from one source and then creates a different kind of energy for it to use. What is the original source of energy that photosynthesis uses?
3. The energy that is created by photosynthesis is in the form of a common, household substance. What is that substance?

a. carbon dioxideb. waterc. sugar