SEED PLANTS

Characteristics of Seed Plants Most seed plants have leaves, stems, roots, and vascular tissue Reproduce by seeds, which contain an embryo and stored food

LEAVES Leaves trap light and make food through photosynthesis Leaves come in many shapes, sizes, and colors!

LEAVES The epidermis is the thin layer of cells on the upper and lower surfaces of a leaf They may have a waxy cuticle coating the epidermis

LEAVES Stomata are small openings in epidermis that allow CO 2, H 2 O, and O 2 to enter and exit leaf. Each stoma is surrounded by 2 guard cells that open and close it.

LEAVES The palisade layer contains chloroplasts where most food is made. The spongy layer is a layer of loosely arranged cells and air.

STEMS Stems allow the movement of materials between leaves and roots. They are usually above ground. They support the branches leaves and flowers. They may store food.

2 KINDS OF STEMS Herbaceous stems are soft and green. Woody stems are hard, rigid, and woody.

ROOTS Roots collect water and nutrients from the ground. Roots anchor plants so they don’t blow away. They may store food or water.

VASCULAR TISSUE Xylem tissue transports water from the roots throughout the plant

VASCULAR TISSUE Phloem tissue moves food from where it is made to other parts of the plant.

VASCULAR TISSUE Cambium tissue produces new xylem and phloem cells.

GYMNOSPERMS Gymnosperms are vascular plants that produce seeds that are not protected by fruit. Gymnosperms are the oldest trees alive.

GYMNOSPERMS Gymnosperms have no flowers. Leaves are often needlelike or scalelike, evergreens.

4 divisions of conifers Conifers Cycads Ginkgoes Gnetophytes

CONIFERS Conifers reproduce by male and female cones.

ANGIOSPERMS Angiosperms are vascular plants that flower and have fruit that contains seeds. Fruit develops from flowers. Most fruits contain seeds.

2 Groups of Angiosperms 1.MONOCOTS have one cotyledon used for food storage inside their seeds. 2.DICOTS have two cotyledons inside their seeds. A cotyledon is part of a seed often used for food storage.

COTYLEDON A cotyledon is part of a seed often used for food storage.

LIFE CYCLES OF ANGIOSPERMS An annual plant’s life cycle is completed in one year. A biennial plant’s life cycle is completed in two years. A perennial plant takes more than two years to grow to maturity.

Importance of seed plants Human life depends on seed plants. –Wood for construction and paper products comes from conifers. –Angiosperms form the basis of diets for most animals, including humans.