2.2: internal leaf structure Flashcards
Structural tissue
Four types: Epidermal Cork Parenchyma Support and strengthening
Epidermal tissue
Protects and covers leaves, roots, stems
Prevents excessive water loss and injury by outside agents
Cuticle layer
Consists of a waxy substance that helps to seal in water, covers epidermal tissue of the shoot system
Root hairs
Absorb water and nutrients for the roots
Cork tissue
Protects and waterproofs the stems and certain roots of woody plants
Parenchyma tissue
Makes and stores food
Support and strengthening tissue
Consists of fibers which run through roots, stems, and large veins of leaves- live only a short time
Vascular tissue
Elongated, tubular cells
Sap-conducting
Stems, petioles, veins, and roots
Sap
Found in vascular tissue
Two types: water with dissolved minerals, food materials
Two types of vascular tissue
Xylem up
Phloem down
Meristematic tissue
Growth and repair
Form various types of structural and vascular tissue
Cambium tissue
Interval and enables stems and roots to grow in diameter (meristematic)
Vascular cambium
Cork cambium
Epidermis
Provides covering and protection for upper and lower leaf surfaces
Stomata
Tiny openings in the epidermis, also leaf pores, regulate transpiration, the loss of water vapor from leaves and stems
Opened and closed by guard cells
Leaf hairs
Hairlike structures in the epidermis
Mesophyll
Middle portion of the leaf, where most of the photosynthesis takes place
Divisions:
Upper palisade mesophyll
Lower spongy mesophyll
Intercellular air spaces
Air spaces between the spongy mesophyll cells
Cell
Basic structural unit of all living things
Cell membrane
Surrounds the cell
Lumen
Cavity surrounded by a membrane
Nucleus
Controls the cell’s activities
Cytoplasm
Fluid medium for the molecules and organelles that make up the cell
Cell wall
Made of cellulose, a complex carbohydrate made up of long chains of glucose molecules- great strength, flexibility, support, protection
Woody stems have lignin in the cell wall
Chloroplasts
“Factories” in the cells of green plants, contain chlorophyll
Vacuoles
Storage structures in cells
Tissue
Living material which is constructed in such a way as to perform a particular task for an organism. Three distinct kinds in plants: Structural Vascular Meristematic
