Life on Land, Eighth Grade, Plant Biology Science Projects (14 results)

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

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

Leaves grow in a different pattern than stems and shoots. They do not elongate along one axis, but instead spread out over time. Do all regions of the leaf grow equally? You can use markings on different regions of a growing leaf to see if the whole surface grows, or if growth is focused in a particular region, like the veins or edges of the leaf. If you look along a leafy stem, you may notice that leaves at different positions along the stem are different sizes. You can do an experiment to… Read more

Soil may look like a bunch of dirt, but good quality soil is actually a complex mixture of dirt, nutrients, microorganisms, insects and worms. What type of benefit do these microorganisms offer a growing plant? You can test this by baking soil in the oven to sterilize and kill the microorganisms. Do plants grown in sterile soil do better than plants in unsterilized soil? What about adding worms to one plant, but not to the other. Will the plant with worms grow better? Some insects are bad… Read more