You will explore plant roots and their various functions through experimentation.
After completing this tutorial, you will be able to complete the following:
The four major parts of a flowering plant include the flower, the leaves, the stem, and the roots. The flower is the primary reproductive structure of the plant, while the stem serves as support for the flower and the leaves, and acts as the plant's plumbing system, conducting water and nutrients from the roots, and food in the form of glucose, from the leaves to the other plant parts. Leaves contain chlorophyll, and are designed to capture sunlight, which the plant uses to perform photosynthesis, producing food for the plant by combining energy from the sunlight, carbon dioxide from the air, and water and dissolved minerals from the soil. Roots are typically the underground portion of a plant. They absorb water and dissolved minerals, anchor the plant in the soil, and sometimes store nutrients for future use. Roots also provide for the movement of nutrients from the soil to the stem of the plant for further distribution; likewise, they transfer food produced through photosynthesis back down to the root cap to promote growth and general root health.
The root system of a flowering plant begins developing from the hypocotyl of the seed embryo. This is where the primary root starts to grow. Roots generally grow downward into the soil, and do not bear leaves. Therefore, no nodes are present.
Two kinds of root systems can be distinguished in flowering plants: taproot systems and fibrous root systems. A dicotyledon has two embryonic leaves, or cotyledons, and typically has a taproot system, while a monocotyledon has only one embryonic leaf, and a fibrous root system.
A taproot system originates from the primary root, which grows vertically down into the soil and is noticeably more substantial than the secondary roots that eventually branch off of it. As the primary root thickens and matures, it is recognized as a taproot. The system of primary and secondary roots together is known as the taproot system.
A fibrous root system develops when the primary root dies at an early stage, and is replaced by numerous, homogenous roots that develop from the stem, forming a sort of web. These roots are approximately uniform in size and shape, and also known as adventitious roots, and are particularly useful for erosion control.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||There are no specific pre-requisite concepts necessary.|
|Type of Tutorial||Experiment|
|Key Vocabulary||absorb, flower, homeostasis, leaf, nutrients, osmosis, photosynthesis, plant, roots, soil, stem, sunlight, transport|