Question

Differentiate between: Xylem and phloem.

Answer 1

Hint: The complex tissues are made up of more than one type of cells. These cells differ from one another in their form and structure; however, these cells work together as a unit Hence a complex tissue can be defined as a collection of structurally dissimilar cells performing a common function or set of functions. These are of two types xylem and phloem.

Complete Answer:
- Xylem: It is the chief water - conducting tissue of the plants. Xylem functions as a conducting tissue for water and minerals from the roots to the top of plants, i.e., to the stems and leaves.
- Phloem: It is a living tissue that carries food materials, (in particular, sucrose, a sugar), from the place it is available (source) to the places where it is needed (sink). It transports the organic materials, usually from leaves to other parts of the plants like roots, growing tips of stems and leaves, flowers, fruits etc. The food prepared in the leaves through the process of photosynthesis needs to be transported to each and every part of the plant body, which is facilitated by this conducting tissue called phloem.

Now let us see the difference between xylem and phloem.

Sl.No	Xylem	Phloem.
1.	It helps to carry water from roots to leaves.	It helps to carry food from the leaves to growing organs and also to the storage organs.
2.	It is usually made up of dead cells.	It is usually made up of living cells.
3.	The cell wall of xylem is thick.	The cell wall of phloem is thin.
4.	The cell wall of xylem is made up of lignin.	The cell wall of phloem is made up of cellulose.
5.	It helps in the passive transport of water.	It helps in the active transport of sugar and food.

Note: Along with acting like a conducting tissue, xylem also provides the mechanical strength to the plant parts Mechanical strength is the ability to tolerate stress, pulling forces, compressive forces etc. without breaking off or tearing off.