1. The Characteristics of Seed Plants
Chapter 8 Section 3
The Characteristics of Seed Plants

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
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: tissue through which food moves
Xylem: tissue through which water and minerals move

4. 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
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
Young plant that develops from the fertilized egg (zygote)
Cotyledon
A seed leaf that sometimes stores food
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 Water Wind Shooting out of a plant
Seeds pass through animal’s digestive system and are deposited in new areas
Barblike structures hook onto an animal’s fur
Water
Seeds that fall into oceans and rivers
Wind
Disperse light weight seeds (dandelions and maple trees)
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
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 Taproot 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
One long, thick main root
Carrots, dandelions, cacti

11. The Structure of a Root Root cap Root hairs
Protects the root from injury during growth
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
Herbaceous
Woody

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

16. Woody Hard and rigid Outermost layer is bark Cambium Sapwood Heartwood
Produces new cells which divide to produce new phloem and xylem
Sapwood
Active xylem that transports water and minerals
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
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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
Process by which water evaporates from a plant’s leaves
Plants retain the water by closing the stomata