Question
Biology Question on Anatomy of Flowering Plants
Why are vascular bundles termed ?closed? in monocots?
A
Xylem and phloem are present.
B
Xylem and phloem occur in separate bundles.
C
Vascular cambium is present between xylem and phloem
D
Vascular cambium is not present.
Answer
Vascular cambium is not present.
Explanation
Solution
The vascular bundles consist of complex tissues, the phloem and the xylem. In dicotyledonous stems, cambium is present between phloem and xylem. Such vascular bundles, because of the presence of cambium, possess the ability to form secondary xylem and phloem tissues, i.e are open to growth and hence are called open vascular bundles. In the monocotyledons, the vascular bundles have no cambium present in them. Hence, since they do not form secondary tissues they are referred to as closed.