Biology 2014 JAMB Past Questions - Question 16: In vascular plants, the sieve tubes and companion cells are present in the

Correct Answer

D

Explanation

Vascular plants such as ferns (pteridophytes) and seed plants (spermatophytes) have vascular tissues consisting of xylem and phloem. The phloem has 3 types of cells namely companion cells, sieve tubes and phloem parenchyma. Movement of manufactured food in the leaves in fluid form occurs through the sieve tubes. Besides each sieve tube are companion cells. xylem has several types of tracheid's, wood pith and xylem parenchyma. The xylem vessels and tracheidsare tubes through which soil solution gets to the leaves of plants. Cambium is a meristem found between the xylem and phloem in dicotyledonous stems. As it divides actively, forms new xylem and phloem tissues resulting in secondary growth or thickening of the stem. C o r t e x is c o m p o s e d of parenchymatous cells. These cells when fully filled with water i.e. turgid function as a supporting tissue.