Question

Fusiform initials form
A. vascular rays
B. Tracheary elements
C. Ray parenchyma
D. Phloem parenchyma

Answer 1

Fusiform initials are the elongate cells that help in producing the conducting cells in both the xylem and phloem of the vascular cambium.

Complete answer:
The fusiform initials are elongated cells, which results in the production of cells that form the vertical system of the secondary phloem and xylem, tracheary elements, fibers, sieve cells, and the associated companion cells. The ray initials are isodiametric cells that are equal in all dimensions, which are likely to produce the vascular rays, and comprise the horizontal system of secondary tissues, which helps in the translocation and storage of food and water.
These cell aids in the divisions of the fusiform and ray initials are primarily tangential, as the new cells are regularly replaced and arranged in well-defined radial rows, which results in the characteristic pattern of the secondary vascular tissues.
The fusiform initials result in the formation of tracheary elements such as tracheid’s, vessels, fibers, sieve tubes. Xylem consists of three major types of cells, the tracheary elements, xylem parenchyma cells, and xylem fiber cells. One of the major cell types in wood-forming xylem is the tracheary elements. They help in conducting water and are responsible for distributing raw sap throughout the plant body. These cells are dead as they mature. The specialized vascular cells form hollow tubes with thickened lignified walls of the secondary cell wall that provide the major structural element in wood.

Hence, the correct answer is option (B).

Note: The thin-walled highly vacuolated cells of the vascular cambium have two types: the fusiform initials, and the ray initials. The fusiform initials are the elongated cells, which form the secondary xylem and secondary phloem. These cells undergo addition division and form the phloem or the xylem mother cell, which differentiates into their respective cell types such as the tracheids, vessels, fibers, sieve tubes, which are collectively known as the tracheary elements.