xylem Two types :1- tracheids vessels 2- The transfer of water and mineral salts from the root to the parts of the plant

TracheidsTracheids - long, slender cells connected to each other by pits. Found in all vascular plants VesselsVessels - shorter, larger diameter cells. Found only in Angiosperms

PhloemPhloem Involved in transport of sucrose, other organic compounds, and some ions from the leaves to other parts of the plant

Two types of cells in the phloem: sieve-tube members companion cells phloem

T.S of Dicot root

T.S Monocot Root

dicot stem

monocot stem

MonocotyledonDicotyledon 1. A large number of vascular bundles. 1. A limited number of vascular bundles. 2. The vascular bundles are scattered in the ground tissue. 2. The vascular bundles are arranged in a ring. 3. No cambium occurs between the xylem and phloem. 3. Cambium occurs between the xylem and phloem. 4. There is no distinction between the cortex and pith. 4. The cortex and pith can be clearly distinguish. Differences between Monocot and Dicot Stems

Epidermis :Functions The epidermis protects the underlying tissues. prevents the desiccation of inner tissues and thus prevents water loss

The cells of this tissue store starch It allows solutions to pass from the vascular bundles to the cortex Functions of the Endodermis

Functions of the Pericycle It strengthens the stem. It provides protection for the vascular bundles

Functions of the Vascular Bundles The xylem provides a passage for water and dissolved ions from the root system to the leaves The phloem transports organic food from the leaves to other parts of the plant. The cambium, divides to produce new xylem and phloem cells

Functions of the Pith The cells of the pith store water and starch. They allow for the exchange of gases through the intercellular air spaces.