Question

The cylinder of tissues lying inside the endodermis of plant stems and roots, containing the vascular tissues, is known as

• A. Pith
• B. Cambium
• C. Stele
• D. Pericycle

Answer 1

The correct option is C Stele

In a vascular plant, the stele is the central part of the root or stem containing the tissues derived from the procambium. These include vascular tissue, in some cases ground tissue (pith) and a pericycle, which, if present, defines the outermost boundary of the stele. Outside the stele lies the endodermis, which is the innermost cell layer of the cortex. The earliest vascular plants had stems with a central core of vascular tissue. This consisted of a cylindrical strand of xylem, surrounded by a region of phloem. Around the vascular tissue there might have been an endodermis that regulated the flow of water into and out of the vascular system. Such an arrangement is termed a protostele.

So the correct option is 'stele'.