Nutrition and Transport in Flowering Plants - The Leaf

Flashcards covering the external and internal structures of a dicotyledonous leaf, including cellular characteristics and functions.

Leaf blade (Surface area)

Large and flat structure that provides a greater surface area-to-volume ratio to enable the leaf to trap the maximum amount of sunlight.

Leaf blade (Diffusion distance)

Large and thin structure that allows rapid diffusion of carbon dioxide to the inner cells due to a short diffusion distance.

Vein network

Transports water and mineral salts from the roots to all cells in the leaf blade and carries manufactured food to other parts of the plant.

Leaf stalk

Holds the leaf blade away from the stem to obtain sufficient light and air.

Leaf arrangement

Organized around the stem in a regular pattern (pairs or alternate) to prevent leaves from blocking each other so each receives sufficient light.

Upper epidermis

A single uppermost layer of transparent cells (without chloroplasts) that protects the inner layer of cells and allows light to penetrate.

Waxy cuticle

A layer covering the epidermis that reduces evaporation of water from the leaf and prevents entry of disease-causing microbes.

Palisade mesophyll

A layer of long, cylindrical, closely packed cells containing numerous chloroplasts where photosynthesis mainly takes place.

Spongy mesophyll

Irregularly shaped, loosely arranged cells with chloroplasts and many air spaces that allow for gas diffusion.

Air spaces

Areas between spongy mesophyll cells that allow rapid diffusion of carbon dioxide and oxygen in and out of the cells.

Thin film of moisture

A layer of water surrounding spongy mesophyll cells so that gases entering the cells can dissolve.

Xylem

Transport tissue within the vascular bundle that carries water and mineral salts.

Phloem

Transport tissue within the vascular bundle that carries manufactured food.