Structures of Seed Plants

Basic Parts

• Root Systems – Includes roots of plant• Shoot Systems – include stems and leaves• These two systems are connected in a plant• Xylem and Phloem transports water and

minerals to all parts of plant

Roots

• Roots supply plant with water and dissolved minerals– Water and minerals are transported through

xylem to the shoots• Roots hold plants securely in the soil• Roots store surplus food during

photosynthesis– Food is made in the leaves and moved to the roots

through phloem

Root Structures

• Surface of the root is called the epidermis– Inner layer of root is vascular tissue

• Root cap protects the tip of the root– Root cap produces a slimy substance that helps

the root to push through the soil

Root Systems

• Taproot System – One main root or taproot– Grows downward to reach water deep in the earth– Smaller roots branch off of this main taproot– Gymnosperms usually have taproots

• Fibrous roots systems have several roots that spread out from the base of the plants stem– Usually get water that is close to the surface

Stems

• Stems connect a plants roots to its leaves and flowers

• Stems support the plant body• Leaves are along the stems or at the ends of

stems. This helps the leaves to get sunlight for photosynthesis

• Stems transport material between the root systems and the shoot systems

Types of Stems

• Herbaceous Stems – Stems that are soft, thin and flexible.– Flowers, crops, house plants

• Woody Stem – Stems that are rigid and made of wood and bark– Trees

Leaves

• Main function of leaves is to make food for the plant

• Leaves can come in all shapes and sizes• Most leaves are green because they contain

chloroplasts. Chloroplasts capture sunlight and use this energy to make food for the plant

Flowers

• Flowers come in many shapes, colors and fragrances

• Flowers are designed to draw in animals and insects to help with pollination

• Flowers that are not brightly colored or have fragrances rely on wind to spread their pollen

• Flowers can also produce nectar that will attract birds and insects. As the animals move from flower to flower they spread the pollen

Flower Parts

• Sepals – Outermost ring of flower parts that usually protect the bud. Often green like other leaves. They fold back when the flower blooms

• Petals – Flat leaf like parts of a flower, usually brightly colored to attract insects or animals

• Stamen – Male part of flower. Has a thin stalk called filament. Filament is topped by an anther. The anther is filled with pollen

Flower Parts Continued

• Pistil – Female parts of a flower. Tip of pistil is called the stigma. Stem of pistil is called the style. Bottom of pistil is called the ovary. Inside the ovary are ovules. Inside each ovule is an egg

• Pollen collects on the stigma. Pollen travels down the style to the ovary of the flower. There the pollen can fertilize the eggs inside each ovule. When the egg is fertilized it will turn into a new seed. The ovary will turn into a fruit.