Question

Short / Long answer type questions.
Answer the following with reference to the anatomy of dicot stem:
(i) Where exactly are the cambial cells located in the vascular bundles?, (ii) What is the name given to such a bundle, (iii) How are the xylem vessels arranged ?, (iv) What type of cells constitute the pith ?

Answer 1

(i) The cambial cells are located between the xylem and phloem. They consist of meristematic cells. The division of these meristematic cells adds to the phloem towards the periphery and xylem towards the centre during the secondary growth.

(ii) Such a bundle is conjoint, open, and with an endarch arrangement.

(iii) Xylem is situated towards the inner side of each vascular bundle. It is endarch type i.e. protoxylem lies towards the pith and metaxylem towards the periphery.

(iv) The central portion of the stem is occupied by a large number of parenchymatous cells which comprise the pith. These cells are rounded in shape and have large intercellular spaces.