Plants • Primary source of energy – Sun -> grass -> deer -> humans • Carbon cycle – Take in carbon dioxide, produce glucose and oxygen • Keep us cool, wind breaks, holds soil in place, provide habitat, building materials, fuel
Parts of a Plant • Four basic parts – Leaves – Stems – Roots – Flowers (fruit/seeds)
Leaves • “Food Factory” through photosynthesis • Vary in shape, size, and arrangement – Help identify plants – Simple, compound – Toothed, pointed, smooth – Lobed, ovate, lanceolate – Whorled, alternate, opposite
Parts of a leaf Petiole – leaf stalk Blade – flat part of the leaf Midrib – large center vein Veins – branch of the midrib and form network • Margins – edges of the plant leaves • •
• Leaf is made of specialized cells • Epidermis – Outer, protect the leaf from loss of moisture • Guard cells responsible for opening and closing stomata • All the plant to breathe – Center, food making • Chloroplast has chlorophyll • Photosynthesis – Process by which carbon dioxide and water in the presence of light are converted to sugar and oxygen
• Food manufactured in leaf moves down through the stem to the roots – Used or stored in stem or root • Sometimes cells in roots, stems, and leaves – Respiration • Oxygen used to produce energy for cells • Too much water can affect efficiency