Plant Structures & Functions

Every flowering plant is built from a small set of structures, and each one has a specific job. The roots anchor the plant and pull in water; the stem holds it up and moves water and food around; the leaves make food using sunlight; and the flower makes seeds so a new plant can grow. Once you know what each part does, you can predict what would happen if a part were missing or damaged.

The Main Plant Structures

• Roots — anchor the plant in the soil and absorb water and minerals.
• Stem — supports the plant and carries water up and sugar back down.
• Leaves — capture sunlight and make food through photosynthesis.
• Flower — the reproductive part that makes seeds.
• Fruit — grows from the flower and protects the seeds inside it.
• Seed — a tiny package with everything needed to grow a new plant.

How a Plant Makes Its Own Food

Plants are special because they do not need to eat — they make their own food. Inside the leaves, green cells called chloroplasts trap sunlight. The plant combines that energy with water from the roots and carbon dioxide from the air to make a sugar called glucose. Oxygen is released as a side product, which is why forests are sometimes called the lungs of the planet.

1. Roots pull water and minerals out of the soil.
2. The stem carries water up to the leaves through tiny tubes called xylem.
3. Leaves combine sunlight, water, and CO2 to make glucose.
4. Glucose travels back through the stem to feed the rest of the plant.
5. Oxygen leaves the plant through tiny pores in the leaves called stomata.

Why Each Part Matters

• No roots: the plant tips over and cannot pull in water.
• No leaves: no photosynthesis, no food, no growth.
• No flowers: no seeds, so the plant cannot reproduce.
• No fruit: the seeds have nothing to protect them as they ripen.