Fourth Grade, Plant Biology Science Experiments (Page 6)

Can Water Plants Be Used to Determine Water Quality?

Science Fair Project Idea

Scientific Method

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

Do Different Tree Species Grow at the Same Rate?

Science Fair Project Idea

Scientific Method

Trees grow more during the early spring than they do the rest of the year. Because of this period of dormancy, or lack of growth, each year of growth is marked by a line called a tree ring. You can count the number of rings in the cross section of a tree trunk to show how old the tree is. You can also count the number of rings in a stem to see the age of a stem or branch. One way to measure the rate of growth of a tree is to count the number of rings per inch. Trees with high numbers of… Read more

Earthworm Castings — The Ideal Proportion in Soil for Young Garden Plants

Science Fair Project Idea

Scientific Method

Everybody knows that worms are good for the soil, but not everybody knows why. Here's a project that investigates just one of the ways earthworms improve the earth. Would earthworm castings (or earthworm manure) help your plants prosper and flourish? If so, how much should you use? Read more

Fruit Ripening

Science Fair Project Idea

Scientific Method

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

Fungi Spores

Science Fair Project Idea

Scientific Method

Mushrooms are not plants, but are fungi. Fungi include mushrooms, molds, and lichen. They do not produce seeds to reproduce like some plants. Fungi produce spores, like more primitive plants do. The spores of a mushroom are contained in the tiny folds around the stem underneath the mushroom cap. Different species of mushrooms have different types of spores, with different colors and different patterns of folds. You can make mushroom prints by removing the stem from a mushroom and placing the… Read more

How Do Flowers Develop?

Science Fair Project Idea

Scientific Method

Flower development is an important part of plant growth. When a plant has reached maturity, it needs to develop flowers in order to reproduce. The male and female parts of the flower have specialized structures for reproduction that develop as the plant matures. How do flowers develop over time? Which structures develop first? You can answer these questions by dissecting the flowers of a gladiola. Gladiola flowers grow and develop along the stem, with the most mature flowers opening at the… Read more

How Does the Stem Grow?

Science Fair Project Idea

Scientific Method

Plant stems grow through a process of elongation due to cell divisions within the stem. Does the entire length of the stem elongate evenly? Or do certain regions along the plant stem grow more or less than others? Regions that are involved in active growth are called vegetative. You can conduct an experiment to show which regions of a bean seedling are involved in vegetative growth. Use a marker to mark one inch sections along the main stem of a young bean seedling. Number the regions 1-6… Read more

It's Crowded in Here! A Study of Plant Population Density

Science Fair Project Idea

Scientific Method

Like humans, plants can be negatively affected by overcrowding. Unlike humans, plants cannot get up and move to a new environment or explore how to utilize new resources. This experiment will explore the effects of crowding (population density) on the growth and health of plants. Read more

Moss is Boss: Using Plants to Determine Direction

Science Fair Project Idea

Scientific Method

Have you ever gone camping, looked up at the stars, and found the Big Dipper? Two stars in the dipper part of this constellation point to Polaris, the north star, which people have used for thousands of years to help them find their way. In this plant biology science fair project, you'll investigate whether plants, like moss, can help you find your way, too. Read more

Rad Radishes: Effects of Irradiation on Seed Germination

Science Fair Project Idea

Scientific Method

DNA is the "instruction manual" for the successful growth of a living thing, from a single cell to a mature adult. When the DNA of an organism is somehow damaged, it can have an impact on the organism's development over time. In this plant science fair project, you will track how irradiation (exposure to radiation) of radish seeds affects germination (sprouting of a seedling from a seed). Read more

Fourth Grade, Plant Biology Science Experiments (64 results)

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