Which one among the following is not a part of vascular bundle in plants?

The correct answer is  Endodermis.

Key Points

• Vascular bundles are crucial components of the transport system in plants, responsible for the movement of water, nutrients, and food.
• They consist mainly of two types of tissues: Xylem and Phloem.
• Xylem is responsible for the transport of water and minerals from the roots to the rest of the plant. It consists of vessels, tracheids, xylem parenchyma, and xylem fibers.
• Phloem is responsible for the transport of organic nutrients, particularly sucrose, from the leaves to other parts of the plant. It consists of sieve tubes, companion cells, phloem fibers, and phloem parenchyma.
• Cambium is a layer of actively dividing cells located between the xylem and phloem in dicotyledonous plants. It is responsible for the secondary growth of stems and roots, increasing their thickness.
• The Endodermis is a single layer of cells that forms a boundary between the cortex and the vascular cylinder in roots. It plays a key role in regulating the flow of water and nutrients into the vascular system but is not considered part of the vascular bundle itself. Hence, statement 1 is correct.

Additional Information

• Vascular bundles are arranged differently in various types of plants. In monocots, they are scattered throughout the stem, while in dicots, they are arranged in a ring.
• There are two main types of vascular bundles:
  • Collateral: Xylem and phloem are arranged on the same radius, with xylem on the inside and phloem on the outside.
  • Bicollateral: Xylem is flanked by phloem on both sides.
• The pericycle, another important structure in roots, is a layer of cells just inside the endodermis. It plays a crucial role in the formation of lateral roots.
• In addition to transport, vascular bundles provide structural support to the plant, helping it maintain its shape and resist various mechanical stresses.