Lesson 50: Basic Plant Structure
Roots, stems, and leaves have varied forms and functions in familiar vascular plants. Comparisons include specialized organs and different root systems, using structure as evidence for identifying plant parts.
Key Ideas
- Many familiar plants have roots, stems, and leaves. These parts work together, although not all plants have the same body plan.
- Plant parts can have different shapes and jobs. A part may look unusual and still be a root, stem, or leaf.
- Pine needles and lily pads are both leaves. A potato is a thickened underground stem that stores food.
- Fibrous roots form many branching roots. A taproot has one main root with smaller roots branching off it; some store food.
Vocabulary
- Roots: Plant parts that usually take in water and minerals and help hold the plant in place.
- Stem: A plant part that supports other parts and carries materials between them.
- Leaves: Plant parts that usually capture light to help make food. Leaves come in many shapes.
- Modification: A plant part with a special shape or job, such as a potato stem that stores food.
- Fibrous Roots: A root system made of many branching roots, like those of grass.
- Taproot: One main root with smaller roots branching from it, like a carrot’s root.
Discussion Questions
- A cactus has spines instead of broad flat leaves, and a desert gets very little rain. Why might a small hard leaf suit a dry place better than a big soft one?
- Grass in a lawn gets cut every week and keeps growing. If you cut the top off a young tree, it usually does not recover the same way. What might be different about where each one grows from?
- Guess, before we study it: what do you think each of the three parts is for? Write your guesses down and keep them.
Supplies
- One healthy starter plant or seedling in its pot. Newspaper, and a magnifier if you have one