Plant Parts and their Functions

Leaves-Internal

Upper and lower epidermis-skin of the leaf that prevents the loss of too much moisture Cuticle: waxy protective coating on outer surface Stomas-small openings under the leaf for breathing or transpiration Guard Cells-open and close stomas

Leaves-Internal Air Space: CO 2 & O 2 Vein: Movement of Fluid Xylem: transport water up Phloem: transport glucose

Leaves-Internal Chloroplasts-small green particles that contain chlorophyll –gives leaves their green color –necessary for photosynthesis

Layers Palisade Layer: column-shaped cells with many chloroplasts (primary site of photosynthesis Spongy mesophyll: loosely packed, irregularly shaped cells surrounded by air spaces, usually found on the underside of the leaf a. Spaces allow gases to move between palisade cells and out of the leaf.

Leaves-Internal

Functions of Leaves Photosynthesis-manufactures food in green plants which is the beginning of the food chain for all living things Photosynthesis is the process by which carbon dioxide and water in the presence of light are converted to sugar and oxygen

672 kCal

Functions of Leaves Respiration: plant leaves, stems and roots consume oxygen and give off carbon dioxide Plants produce much more oxygen through photosynthesis than they use through respiration

Stems Movement of Materials Support of the leaves and reproductive structures Food storages Reproduction with stem cuttings or grafting

Stems-Internal

Pith-dead center of stem for support (Black) Heartwood-old inactive xylem (Brown) Sapwood-new active xylem (Blue) Cambium-thin, green, actively growing tissue located between bark and wood and produces all new stem cells (Purple) Phloem-active (Green) Bark-old inactive phloem (Black)

Stems-Internal Dicot: example: trees Monocot : examples: corn, grasses

Monocot Bundle

Functions of Stems Translocation – move water and minerals from roots up to leaves & move food/nutrients from leaves down to the roots Xylem and phloem cells help with this process.

Stems-Internal (Translocation) Xylem-tissue that transports water and nutrients up from the roots to stems and leaves Phloem-tissue that transports food down from leaves to roots Phloem Xylem

Functions of Stems, Leaves & Roots Transpiration – loss of water through the leaves or stems of plants Transpiration exchange gases as oxygen and carbon dioxide Occurs in stomas and lenticels

Functions of Flowers Produce seeds used for sexual reproduction Attract insects for pollination (Pollination is the transfer of pollen from anther to stigma.) Produce fruit (ripened ovary) to protect, nourish and carry seeds Reproduction: increasing plant numbers usually from seeds

Root 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

Roots-Internal Much like stems in that they have a phloem, cambium, and xylem layer Phloem-the outer layer that carries food down the root Xylem-the inner layer that carries water and minerals up to the stem

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