Plant Parts & Their Jobs

Plant Jobs Primary source of food for people and animals Write these down… Primary source of food for people and animals Produce oxygen Absorb carbon dioxide Continued…

Plant Jobs Slow wind speed Provide homes for wildlife Prevent erosion Beautify surroundings Furnish building materials and fuel

Parts of a plant Four basic parts LEAVES STEMS ROOTS FLOWERS Draw this on your notes Four basic parts LEAVES STEMS ROOTS FLOWERS

LEAVES

LEAVES The greenest part of the plant Act as solar collectors Large leaves= areas of little sunlight Tiny leaves = bright sunlight Needles = no water loss

LEAVES - structure Epidermis - top and bottom tough layer Pallisade Layer - most cells with chloroplasts are found here Spongy Layer - gas exchange through stomata

LEAVES - 2 functions Make Food (sugar) in the chloroplasts Gas Exchange take in carbon dioxide and release oxygen and water vapor Stomata on the bottom of the leaves have guard cells that open and close as they fill up with water.

LEAVES - photosynthesis Plants make sugar using CO2 (from air) and H2O (from roots) as ingredients.

STEMS

STEMS - two main functions Liquid transport xylem cells carry water & minerals up phloem cells carry food down Support

STEMS – example Dicot plants such as a bean (xylem & phloem in a ring under the bark) Cambium Phloem Xylem

STEMS – example Monocot plants such as a corn stalk (vascular bundles scattered throughout the setm) Phloem Cells Xylem tube

What Good Are Stems to humans? FOOD-rhubarb, celery, white potato WOOD – building and fuel PAPER

Types of Modified Stems Bulbs: (onion) Tubers: (potato) Stolons: above ground runner (strawberry) Rhizomes: below ground runners (field bindweed or creeping jenny)

ROOTS

ROOTS - functions Anchor plant Suck up water and minerals Store Sugar (radish, carrot, beets) Reproduction (eyes on potatoes)

ROOTS - structure root cap-protects tender cell division area as the root pushes through soil

ROOTS – root hairs Water and minerals move into root by osmosis / diffusion

FLOWERS, FRUITS, SEEDS

FLOWERS, FRUITS, SEEDS Main jobs involve reproduction Attract pollinators Disperse pollen Fertilization Disperse seeds

FLOWERS, FRUITS, SEEDS POLLEN normally carried by insects or wind FRUITS & SEEDS normally carried by wind, animals, water or shot away from parent plants (projectiles)