2.3.1 Plant tissues

What tissues make up the leaf as a plant organ?

Epidermis, palisade mesophyll, spongy mesophyll, xylem, phloem, and guard cells (control stomata opening/closing).

What is the feature of epidermal tissue?

Covered with a waxy cuticle.

What is the function of epidermal tissue?

Reduces water loss by evaporation, as the waxy cuticle prevents water moving out.

What is the feature of palisade mesophyll tissue?

Contains many chloroplasts.

What is the function of palisade mesophyll tissue?

Photosynthesis occurs rapidly; cells are at the top of the leaf to get lots of light.

What is the feature of spongy mesophyll tissue?

Contains many air spaces.

What is the function of spongy mesophyll tissue?

Allows gases to diffuse in and out of cells.

What is the structure of xylem tissue?

Made of dead cells joined together in a continuous tube, strengthened with lignin, with holes called bordered pits.

What is the function of xylem tissue?

Transports water and mineral ions from roots to stems and leaves (transpiration stream). Lignin strengthens and waterproofs the tube.

What is the structure of phloem tissue?

Elongated living cells with sieve plates and little cytoplasm so cell sap can move through.

What is the function of phloem tissue?

Transports food substances in both directions (from leaves to use/storage). This is called translocation.

What is the feature of meristematic tissue?

Cells can differentiate into different types of plant cell.

What is the function of meristematic tissue?

Allows the plant to grow at the tips of roots and shoots.