Unit 3 Parts of the Plant and Their Functions Plant life is essential for life on earth. -Plants provide food, oxygen, and enjoyment Plants are made up of four basic parts 1. Leaves 2. Stems 3. Roots 4. Flowers

Leaves Leaves are the food factory of the plant. External Leaf Structure Petiole - leaf stalk Blade - usually the flat part Veins – structural frame Margin-edge of leaf

Parts of a leaf

Leaves help in the identification of horticulture plants.

6CO2 + H2O + Sunlight = C6H12O6 + 6O2 Internal Leaf Structure Epidermis-skin of the leaf Chloroplasts-process food Photosynthesis - is the process by which carbon dioxide and water in the presence of light are converted to sugar and oxygen. Carbondioxide+water+sunlight=sugar+oxygen 6CO2 + H2O + Sunlight = C6H12O6 + 6O2 Guard Cells Open and Close stoma to allow the leaf to exchange gases

Stems 2 Main Functions Movement of materials Support the leaves and reproductive structures Also used for food storage, reproduction methods External Stem Structure Terminal Bud Axillary Bud Bud Scale Scar Lenticle

Cross Section of a Stem Internal Stem Structure Phloem – manufactured food travels down Xylem – water and minerals travel up Cambium – produces the new stems Cross Section of a Stem

Roots Functions Anchor the plant and hold it Upright Absorb water and minerals from the soil and conduct them to the stem Store large quantities of plant food Propagate or reproduce some plants

Flowers Complete Flower – 4 Main Parts Both Male and Female Parts Incomplete Flower – has only the male or female parts. 4 Main Parts Sepals – protect the flower bud Petals – leaves (attract insects) Stamens – Male reproductive parts Pistil – Female Parts