Question
Question: The type of vascular bundles in the stem of Dracena A.Amphivasal B.Bicollateral C.Amphicribral...
The type of vascular bundles in the stem of Dracena
A.Amphivasal
B.Bicollateral
C.Amphicribral
D.Radial
Solution
The tissue system includes vascular tissues i.e. xylem and phloem. The xylem and phloem strands are usually found in bundles called vascular bundles. The main function of vascular bundles is conduction of water and minerals, translocation of organic solutes and to give mechanical support to the plant body.
Complete answer:
The following terms are commonly used to designate the types of vascular bundles and arrangements of xylem and phloem
1.Radial: the xylem and phloem strands alternate with each other separated by parenchymatous cells. Such kinds of vascular bundles are called radial and found mainly in roots.
2. Conjoint: a vascular bundle having both xylem and phloem together is called conjoint. Normally the xylem and phloem occur in radius. They occur in stems.
3. Collateral: a vascular bundle in which the phloem lies towards outer side and xylem towards inner side, is called collateral ( eg. Sunflower)
4. Bicollateral: a vascular bundle having the phloem strands on both outer and inner side of xylem, is called bicollateral.( eg. Cucurbita)
5. Concentric: a vascular bundle, in which one tissue is completely surrounded by the other, is called concentric. The concentric bundles are of two types-
(a) Amphivasal: the phloem lies in the center and remains completely surrounded by xylem .
(b) Amphicribral : the xylem lies in the center and remains completely surrounded by phloem.
So, the correct answer is option A. Amphivasal
Additional information:
Open vascular bundle: if the cambium is present in the vascular bundle, it is called open.
Closed vascular bundle: if the cambium is absent the vascular bundle is called closed.
Note:
Dracaena plant is a popular ornamental house plant, grown both indoors and outdoors in subtropical climates. Belongs to monocot and asparagus family.