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Third Grade, Plant Biology Science Projects (20 results)

Plants provide us with so much — oxygen to breath, food to eat, materials to make clothing and paper, and beautiful flowers and leaves to admire! How can plants be so diverse and survive in so many kinds of climates? How do they know how to grow towards the sun? Why do some plants not have seeds? Explore the amazing and beautiful world of plants.

Plant Biology
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Science Fair Project Idea
What do plants need to grow? Most of us would answer that they need light, air, water, and soil. But by using a process called hydroponics, you can grow plants without soil! How does it work? Try this project and see for yourself! Read more
Science Fair Project Idea
Plants need nitrogen to grow healthy stems and leaves. Although nitrogen is the most abundant element in the air we breathe, that form of nitrogen cannot be used by plants. Nitrogen contained in fertilizer, on the other hand, is readily taken up by plants. In this experiment, you will compare plants grown without nitrogen fertilizer to plants grown with nitrogen fertilizer. Read more
Science Fair Project Idea
To be able to live on Mars, humans need breathable air, clean water, and nutritious food. Spacesuits can provide oxygen to breathe, ice on Mars can be a source of water, but how could we get nutritious food? Today's astronauts bring food with them. But a manned trip to Mars would require food that was either successfully grown in space or on Mars, as taking the extra weight of food for such a long time—it takes 6–9 months one way—is just too costly. In this project, you will… Read more
Science Fair Project Idea
Fuzzy things are often cute, but not when that fuzziness is mold on your strawberry—yuck! Companies look for natural, plant-based ways to protect the berries from mold when they are in the store, waiting for you to purchase them. Would washing them in aloe vera juice protect strawberries from mold? Do this project and find out! Read more
Science Fair Project Idea
You might not know it, but plants are able to sense their environment and actually respond appropriately. One of the key parameters that every plant must respond to is the direction of gravity: stems go up (opposite to the pull of gravity) and roots go down (in the same direction as the force of gravity). In this project, you will construct simple devices that hold several germinating seeds, which allow you to watch how growing rootlets respond as you rotate the devices, effectively altering… Read more
Science Fair Project Idea
Have you ever enjoyed eating a tasty sweet potato? They can be served as yummy mashed sweet potatoes with melted butter, turned into golden-brown sweet potato fries, or prepared in many other scrumptious ways. Did you know that you can make a sweet potato grow into a sweet potato plant, and grow several sweet potatoes this way? In this science project, you will grow your own sweet potato plants and investigate what part of the sweet potatoes is needed to grow the plants. Read more
Science Fair Project Idea
Everyone loves the beautiful colors of fall, but where do they come from and how does the change in colors happen? In this project, you will uncover the hidden colors of fall by separating plant pigments with paper chromatography. What colors will you see? Read more
Science Fair Project Idea
Fruit is a strategy some plants use to attract animals to disperse seeds. The animals eat the fruit and disperse the seeds through the digestive system. To attract animals, fruit needs to ripen and develop an odor that acts as an attractant. How much more successful are ripe fruits at attracting animals? Try setting out an over and under ripe piece of fruit, and compare how many many insects are attracted to each fruit. How does ripening occur? You can do an experiment using a very ripe… Read more
Science Fair Project Idea
We all know that plants need sunlight and water to grow big and tall. But did you know that inside seeds are baby plants, and that the fragile baby plant inside the seed needs to be protected? If you've ever had a sunburn, you also know that the sun gives off harmful radiation and heat. How much radiation and heat can a seed handle? Find out using some radish seeds, an oven, and your microwave! Read more
Science Fair Project Idea
Some plants grow only in water-logged environments. These plants are usually native to wetlands and are important for the sustainability of aquatic ecosystems. Wetland ecosystems are very fragile and susceptible to the toxic dumping of sewage and fertilizer run-off from neighboring farm land. One very common aquatic plant called duckweed inhabits many wetland marshes. Duckweed grows by asexual reproduction and floats at the surface of the water with tiny roots extending into the water below.… Read more
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