Question

Match and answer correctly.

List I: Type of protoxylem	List II: Plants
A. Monarch	1. Nicotiana
B. Diarch	2. Pisum
C. Triarch	3. Cicer
D. Tetrarch	4. Trapa

A. A-4, B-1, C-2, D-3
B. A-1, B-4, C-2, D-3
C. A-3, B-1, C-2, D-4
D. A-2, B-3, C-4, D-1

Answer 1

Hint: The first formed primary xylem elements are called protoxylem and the later formed primary xylem is known as metaxylem.

Complete answer:
- The vascular bundle is made up of xylem and phloem. Their relative positions differentiate between the different plant groups. Xylem is made up of protoxylem and metaxylem. The stem protoxylem lies toward the centre and the metaxylem lies towards the periphery of the organ.
- Monarch- means single protoxylem. For example: Trapa
- Diarch - means two protoxylems. For example: Nicotiana
- Triarch - means three protoxylems. For example: Pisum
- Tetrarch - means four protoxylems. For example: Cicer

Hence the correct answer is A.

Additional information:
- Xylem is also known as complex permanent tissue that conducts the upward movement of water and minerals from root to plants. Xylem is formed by four types of different elements, that are tracheids, vessels, xylem fibres and xylem parenchyma.
- Tracheids are long tubular dead wells with wide lumen and tapering ends. The cell wall is thick with lignin.
- Vessels are long tubular structures that are placed above one another. The presence of vessels is a characteristic feature of angiosperm.
- Tracheids and vessels are main water transporting elements.vessels are more efficient than tracheids
- Xylem fibres are non living cells with very thick lignin deposition on the walls.
- Xylem parenchyma are living cells with cellulosic cell walls.

Note: Tissue is a group of cells with common origin, structure and function that work together to perform a particular function.