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Structure and Function of Living Organisms. Plant Systems. Leaves. Flowers. Stem. Fruit/Seeds. Roots. Functions of Roots. 1. Anchor the plant 2. Absorption of water and minerals 3. Storage of food. Types of Roots -- Fibrous. Types of Roots -- Tap. Absorption of water and minerals .
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Structure and Function of Living Organisms Plant Systems
Leaves Flowers Stem Fruit/Seeds Roots
Functions of Roots • 1. Anchor the plant • 2. Absorption of water and minerals • 3. Storage of food
Absorption of water and minerals • When the concentration of water is greater outside of the root cells than inside, water moves inside
Xylem • Tubes that carry water and minerals from the roots to where photosynthesis will occur • Xylem Up!!
Phloem • Tubes that carry sugar to areas in the plant where it will be used or stored. • Phloem Down!!
Roots that fix nitrogen from the air • Symbiotic relationship -- two organisms live together and benefit each other • Rhizobium bacteria and roots
Root Nodules • Swellings (bumps) on their roots • Rhizobium bacteria live in these bumps • they take nitrogen from the air and combine it with oxygen to make it useable to the plant • puts nitrogen in the soil so that crops that grow there later may use the nitrogen
Legumes • The group of plants that can do this • Soybeans, clover, alfalfa, beans, peas
Functions of Stems • 1. Transportation of sugar to where it will be used or stored • 2. Transportation of water from the roots to where photosynthesis will take place. • 3. Support the plant • 4. Storage of food • 5. Display of leaves and flowers • 6. Some Photosynthesis
Transportation • 1. Xylem -- tubes that carry water and minerals from the roots to where photosynthesis will occur • 2. Phloem -- tubes that carry sugar to areas in the plant where it will be used or stored.
Types of stems -- Woody • Hard, made of dead xylem • Annual rings -- the size of the xylem change throughout the year leaving light and dark bands • Dark bands -- xylem small and tightly packed; formed during low water (i.e., late summer, fall) • Light bands -- xylem large; formed during periods of high moisture (i.e., spring, early summer)
Phloem New Xylem Old Spring Xylem Old Fall Xylem Annual Ring
Herbaceous • Soft and green • Annuals, and new shoots on perennials
Functions of Leaves • 1. Capture light energy for photosynthesis • 2. Exchange gases between plants and air • 3. Control the loss of water • 4. Storage of food (used as feed for animals and humans)
Capturing light for photosynthesis • Photosynthesis Water + Carbon dioxide ------> Sugar and Oxygen • Palisade layer -- full of cells containing Chloroplasts • Chloroplasts -- where light dependent reaction takes place
The Vascular bundle • Xylem -- Brings water and minerals to the chloroplast • Phloem -- takes sugar and water away from the chloroplast
Forces that move the water • Root pressure • Capillarity • Cohesion -tension theory • Transpiration
Exchange of gasses • Stomata -- openings on the underside of a leaf • Guard cells -- control the opening and closing of the stomata • Spongy layer -- spaces where gas can move about
Controlling the loss of water • Cuticle -- a waxy layer on the top layer • Guard cells and stomata • Transpiration
Plant Reproduction Sexual Reproduction: • Uses meiosis • Uses Fertilizaton: The uniting of the sperm and egg.
Plant Reproduction • Asexual • Creates a new plant without joining sperm and egg.
Parts of a Flower • Receptacle • Provides support for the flower • Perianth