Question

In which portion of Cycas diploxylic vascular bundles are found?
A. Root
B. Stem
C. Leaflet
D. Rachis and leaflet

Answer 1

Hint: Diploxylic means an arrangement of vascular bundle, where two types of xylem are present. These are the centripetal xylem and centrifugal xylem.

 Complete answer:
In Cycas, rachis and leaflets have a diploxylic arrangement in vascular bundles.
Here, two types of xylem are found, usually at the stem cortex:
Centrifugal xylem that is present towards the centre.
It is seen in the leaf trace.
As the leaf-traces enter the leaf and rachis separate, centripetal xylem can be found.
It is present towards the outside.

So, the correct option is D. Rachis and leaflet.

Note: Vascular bundle is a transport system in the vascular plants that are made up of two forms of vascular tissue – xylem and phloem.
Xylem mainly transports water and few nutrients while phloem transports certain organic compounds.