Presentation on theme: "Chapter 8 – Section 3 The Characteristics of Seed Plants."— Presentation transcript:
Chapter 8 – Section 3 The Characteristics of Seed Plants
What are Seed Plants? Seed plants outnumber seedless plants 10 to 1 Have vascular tissue Use pollen and seeds to reproduce
Vascular Tissue Meets the Challenges – stand up straight, supply all cells with food and water. Phloem – food moves through this tissue Xylem – water and minerals travel through this tissue
Pollen and Seeds Do not have to live in water as don’t have sperm that has to swim Pollen-tiny structures that contain the cells that later become the sperm Seeds are made when the sperm fertilizes the egg. –Young plant inside a protective covering, Right conditions sprout breaks out of seed.
Seed Structure – Figure 10 p parts Embryo – plant that develops from zygote Seed food – some stored in cotyledons (seed leaves in embryo) or outside the embryo Seed coat – outer covering (protects from drying out)
Seed Dispersal- scattering of seeds Other organisms waste Barbs that hook on other animals Wind Eject from plant with force
Seed Germination- when embryo begins to grow again and pushes out of seed Begins when seed absorbs water and begin to grow Roots grow first downward, stem and leaves upward Seedling- when you see the leaves Distance from parent needed
Roots 3 Main functions Anchor a plant to ground Absorb water and minerals from the soil Sometimes store food
Types of Roots- Figure 13 p Fibrous Root System- several root systems that form a dense tangled mass- grass 2.Taproot Root System – One long thick root smaller branching off. dandelion
Structure of Root-figure 13 p. 267 Tip round, covered by root cap (protects from injury from rocks as it grows) Root hairs absorb the water and minerals, help anchor plant Vascular tissue –water moves to xylem and upward Phloem – transports food from leaves to roots
Stems – carries substances between roots and leaves supports holds up leaves to get sun
Stem structure- figure p. 268 Herbaceous – no wood Woody hard, rigid several layers, outer layer bark Cambium – cells that divide to procduce phloem and xylem (wood part) All have phloem and xylem
Annual Rings Made up of xylem Summer grow slow and make small rings Spring grow fast and make dark large rings
Leaves Capture suns energy and carry out the food making process of photosynthesis Come in many different shapes
Structure of Leaf- figure 16 p. 270 Surface layers –Protect cells –Veins that contain xylem and phloem –Have stomata (pores that open and close to control gases going in and out) CO2 in and H2O and Oxygen out.
Leaf and Photosynthesis Upper surface has most cells with chloroplasts (chlorophyll in the chloroplasts trap sun’s energy) CO2 enters through stomata H2O through the xylem in stem Sugar and Oxygen produced from CO2 and H20 Oxygen out through stomata Sugar through plant in phloem
Controlling Water Loss Transpiration – water evaporates from plant’s leaves –Close stomata when leaves start to dry out.