Revision: Structural Organisation in Animals and Plants >> Anatomy of Flowering Plants Biology (Theory) ISC (Science) ISC Class 11 CISCE

Meristematic tissue is a group of cells that constantly divide and produce cells indefinitely throughout the life of the plant.

Permanent tissue refers to a group of cells which temporarily or permanently cease to divide and thus assume permanent form and function

• Meristematic tissue consists of cells that can divide and is restricted to specialised regions of the plant.
• Apical meristem is found at the root and shoot tips, is a primary meristem and increases the length of the plant.
• Intercalary meristem is found between mature tissues, is a primary meristem and helps form branches and flowers.
• Lateral meristem is found in mature regions, is a secondary meristem and is responsible for secondary growth (e.g. vascular cambium, cork cambium).
• Axillary bud is present in the axils of leaves and is responsible for forming branches or flowers.

• Epidermal tissue is the outermost covering of the plant body, made up of epidermal cells, stomata, trichomes and root hairs.
• Epidermis is a single layer of compactly arranged parenchymatous cells covered with a waxy cuticle (absent in roots) to prevent water loss.
• Stomata regulate transpiration and gaseous exchange; each stoma has two bean-shaped guard cells (dumb-bell shaped in grasses).
• Stomatal apparatus = stomatal aperture + guard cells + subsidiary cells.
• Root hairs are unicellular extensions of epidermal cells that absorb water and minerals from the soil.
• Trichomes are stem hairs that may be branched, unbranched or secretory, and help prevent water loss.