Fourth Grade, Plant Biology Science Experiments (Page 4)

Bacteria Can Fix It! A Comparison of Nitrogen-Fixing Bacteria and Nitrogen Fertilizers

Science Fair Project Idea

Scientific Method

Do you know what plants need to grow? Sure, they need soil, water, and sunshine. Everyone knows that. But here's a secret: they also need nitrogen. Plants use nitrogen to make DNA in their cells and the proteins that lead to healthy stems and leaves. The problem is, although the Earth's atmosphere is made up of 78% nitrogen, the form of nitrogen found in the atmosphere cannot be used by plants. So how do plants get their nitrogen? Either through nitrogen deposits in the soil, or through… Read more

Can Aloe Juice Save Your Berries from Mold?

Science Fair Project Idea

Scientific Method

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

Chlorophyll Extraction

Science Fair Project Idea

Scientific Method

Chlorophyll is a natural pigment found in green plants. It is the primary pigment that absorbs light energy from the sun for photosynthesis. This energy is then used by the plant to synthesize glucose from carbon dioxide and water. Chlorophyll in the leaves of plants can be extracted and separated using chromatography. A good source of chlorophyll for an extraction is a dark green leafy vegetable like spinach. Rub a fresh spinach leaf on the bottom of a strip of filter paper. You can get a… Read more

Cryopreservation: Freezing Plant Tissues

Science Fair Project Idea

Scientific Method

Cryopreservation—storing seeds in ultra-cold liquid nitrogen—is one method for maintaining plant genetic stocks in seed banks. Can seeds withstand a really deep freeze and still germinate? Read more

Experiment with Factors that Affect Roundup® Weed Killer

Science Fair Project Idea

Scientific Method

Farmers are constantly battling various types of weeds that compete with the crops they are trying to grow. One of the tools they use to combat unwanted plants is a chemical called glyphosate. Glyphosate is the active ingredient in Roundup, a widely used weed killer. In this plant biology science fair project, you will explore the factors that affect the activity of glyphosate. Read more

Germination

Science Fair Project Idea

Scientific Method

Germination is the process by which a seed emerges from the seed coat. Many different variables can effect the process of germination. Try to sprout seeds from different species of plant to see if different species vary in germination time. Are weeds faster germinators than vegetables? Try measuring seeds and then germinating them to see if big seeds sprout at a different rate than small seeds. Try sprouting seeds in different environments to test the effect of different environmental… Read more

Harmful or Helpful? The Effects of Hydrogen Peroxide on the Roots of Plant Cuttings & on Seed Germination

Science Fair Project Idea

Scientific Method

Hydrogen peroxide (often used as a disinfectant) has also been approved for use in pesticides. This science fair project investigates whether hydrogen peroxide has any effects on seed germination or on roots of plant cuttings. Read more

How Do Plants Change the Buildup of Greenhouse Gases?

Science Fair Project Idea

Scientific Method

Global warming is how scientists describe the gradual warming of our global climate. Scientists think that the trend towards global warming can be attributed to the build up of greenhouse gases in the earth's atmosphere from industrialization. Another problem is deforestation, as we remove plants and trees from the environment to meet a high demand for lumber or by clear cutting fields for farming and urbanization. By removing trees from the earth's environment, are we changing how greenhouse… Read more

How Many Seeds Do Different Types of Fruit Produce?

Science Fair Project Idea

Scientific Method

Do you like your strawberry jelly with or without the seeds? Are you glad to have a seed-free watermelon, or do you enjoy spitting the seeds into the garden? You might not like to find seeds in your fruit, but fruit is the plant's way of dispersing seeds to make new plants. How many seeds can be dispersed for each type of fruit? As they say, in one end and out the other! Read more

How Many Seeds Do Different Types of Fruit Produce?

STEM Activity

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Do you like your strawberry jelly with or without the seeds? Are you glad to have a seed-free watermelon, or do you enjoy spitting the seeds into the garden? You might not like finding seeds in your fruit, but fruit is a plant's tool for dispersing seeds to create offspring. In this activity you will investigate how many seeds can be dispersed for each type of fruit. Based on the number of seeds they produce, how productive do you think some of your favorite fruits are? … Read more

Fourth Grade, Plant Biology Science Experiments (64 results)

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