Collateral Vascular Bundles:
Collateral vascular bundles are found in dicotyledonous plants, where the xylem and phloem are arranged in separate regions. They consist of a ring of xylem cells on the inner side and a ring of phloem cells on the outer side. The cambium, a layer of actively dividing cells, is present between the xylem and phloem.

Structure:
1. Xylem: The xylem is located towards the inner side of the bundle and consists of tracheids, vessels, fibers, and parenchyma cells. It is responsible for the transport of water and minerals from the roots to the rest of the plant.

2. Phloem: The phloem is located towards the outer side of the bundle and consists of sieve tubes, companion cells, fibers, and parenchyma cells. It is responsible for the transport of organic nutrients, such as sugars and amino acids, from the leaves to other parts of the plant.

3. Cambium: The cambium is a layer of meristematic tissue located between the xylem and phloem. It is responsible for the production of new xylem and phloem cells, allowing the vascular bundle to increase in size.

Bicollateral Vascular Bundles:
Bicollateral vascular bundles are found in monocotyledonous plants, where the xylem and phloem are arranged in separate regions but on both sides of the bundle. They consist of a ring of xylem cells on the inner side, a ring of phloem cells on the outer side, and an additional ring of phloem cells on the inner side.

Structure:
1. Xylem: The xylem is located towards the inner side of the bundle and consists of vessels, fibers, and parenchyma cells. It is responsible for the transport of water and minerals.

2. Inner Phloem: The inner phloem is located towards the outer side of the bundle but on the inner side of the xylem. It consists of sieve tubes, companion cells, fibers, and parenchyma cells.

3. Outer Phloem: The outer phloem is located towards the outer side of the bundle and consists of sieve tubes, companion cells, fibers, and parenchyma cells. It is responsible for the transport of organic nutrients.

4. Cambium: The cambium is present between the xylem and inner phloem, as well as between the inner and outer phloem. It is responsible for the production of new xylem and phloem cells, allowing the vascular bundle to increase in size.

Differences:
1. Arrangement: In collateral vascular bundles, the xylem and phloem are arranged on opposite sides of the bundle, while in bicollateral vascular bundles, there is an additional ring of phloem on the inner side of the xylem.

2. Presence of Inner Phloem: Bicollateral vascular bundles have an additional ring of phloem on the inner side of the xylem, which is not present in collateral vascular bundles.

3. Location of Cambium: In collateral vascular bundles, the cambium is present between the xylem and phloem, but in