1. THE CHARACTERISTICS OF SEED PLANTS CHAPTER 8 SECTION 3

2. WHAT IS A SEED PLANT? Seed plants outnumber seedless plants Produce much of the oxygen we breathe All seed plants have roots, stems, and leaves The plants that you see are the sporophytes, the gametophytes are microscopic 2 important characteristics 2 important characteristics Vascular tissue Use pollen and seeds to reproduce

3. VASCULAR TISSUE Helps support plants Food, water, and nutrients are transported through the plant Two types of vascular tissue Phloem: Phloem: tissue through which food moves Xylem: Xylem: tissue through which water and minerals move

4. POLLEN AND SEEDS POLLEN AND SEEDS Do not need water for sperm to swim to eggs Instead, seed plants produce POLLEN Tiny structures that contain cells that will later become sperm cells Pollen delivers sperm cells directly near eggs… fertilization occurs… seeds then develop Seed Seed A structure that contains a young plant inside a protective covering

5. HOW SEEDS BECOME NEW PLANTS Inside a seed is a partially developed plant Seed lands in favorable area, the plant sprouts out of the seed and begins to grow Seeds need light, water, and nutrients to grow

6. SEED STRUCTURE Three main parts Embryo Embryo Young plant that develops from the fertilized egg (zygote) Cotyledon Cotyledon A seed leaf that sometimes stores food Seed coat Seed coat Keeps the seed from drying out Acts like plastic wrap In many plants, the seeds are surrounded by a structure called a fruit

7. SEED DISPERSAL Animals Animals Seeds pass through animal’s digestive system and are deposited in new areas Barblike structures hook onto an animal’s fur Water Water Seeds that fall into oceans and rivers Wind Wind Disperse light weight seeds (dandelions and maple trees) Shooting out of a plant Shooting out of a plant

8. GERMINATION Occurs when the embryo begins to grow again and pushes out of the seed Seed absorbs water from environment Seedling Seedling When you are able to see a plants leaves Better chance of living when seedling is far away from parent

9. ROOTS Anchor a plant into the ground Absorb water and minerals from the soil Sometimes store food

10. TYPES OF ROOTS Fibrous root system Fibrous root system Similarly sized roots that form a dense, tangled mass Take much soil with them when pulled out of ground Lawn grass, corn, onions Taproot system Taproot system One long, thick main root Carrots, dandelions, cacti

11. THE STRUCTURE OF A ROOT Root cap Root cap Protects the root from injury during growth Root hairs Root hairs Increase the amount of water and minerals absorbed by the root Water and nutrients are absorbed from the soil and move quickly to the xylem Phloem transports food manufactured in the leaves to the root

13. STEMS Carries substances between the plant’s roots and leaves Support the plant and holds up the leaves so they are exposed to the sun

14. THE STRUCTURE OF A STEM Two types Two types Herbaceous Woody

15. HERBACEOUS Contain no wood and are soft Coneflowers and pepper plants

16. WOODY Hard and rigid Outermost layer is bark Outermost layer is bark Cambium Cambium Produces new cells which divide to produce new phloem and xylem Sapwood Sapwood Active xylem that transports water and minerals Heartwood Heartwood Old, inactive, xylem that provides support to Maple trees and roses

18. ANNUAL RINGS One year’s growth of a tree is represented by one pair of light and dark rings in the tree’s stem Page 269

19. LEAVES Capture the sun’s energy and carry out the food- making process of photosynthesis

20. THE STRUCTURE OF A LEAF

21. THE LEAF AND PHOTOSYNTHESIS Cells that contain the most chloroplasts are located near the leaf’s upper surface Chlorophyll in the chloroplasts traps the sun’s energy

22. CONTROLLING WATER LOSS Transpiration Transpiration Process by which water evaporates from a plant’s leaves Plants retain the water by closing the stomata