plant transport

Wax cuticle

Protective layer on top of the leaf that prevents water from evaporating

Upper epidermis

Thin and transparent layer that allows light to enter the palisade mesophyll layer underneath

Palisade mesophyll

Column-shaped cells tightly packed with chloroplasts to absorb more light and maximise photosynthesis

Spongy mesophyll

Contains internal air spaces that increase surface area to volume ratio for diffusion of gases (mainly carbon dioxide)

Lower epidermis

Contains guard cells and stomata

Guard cell

Absorbs and loses water to open and close the stomata, allowing carbon dioxide in and oxygen out

Stomata

Where gas exchange takes place; opens during the day and closes at night; water also evaporates from here; mostly found on the underside to reduce water loss

Vascular bundle

Contains xylem and phloem to transport substances to and from the leaf

Xylem

Transports water into the leaf for photosynthesis and transpiration

Phloem

Transports sucrose and amino acids around the plant

Large surface area (leaf)

Increases surface area for diffusion of carbon dioxide and absorption of light for photosynthesis

Thin

Allows carbon dioxide to diffuse quickly to palisade mesophyll cells

Chlorophyll

Absorbs light energy so that photosynthesis can take place

Network of veins

Allows transport of water to the cells of the leaf and carbohydrates from the leaf

Stomata (adaptation)

Allows carbon dioxide to diffuse into the leaf and oxygen to diffuse out

Epidermis is thin and transparent

Allows more light to reach the palisade cells

Thin cuticle made of wax

Protects the leaf without blocking sunlight

Palisade cell layer at top of leaf

Maximises absorption of light as it hits chloroplasts directly

Spongy layer

Air spaces allow carbon dioxide to diffuse through the leaf, increasing surface area

Vascular bundles

Thick cell walls in the tissue help support the leaf and stem