Question

The exarch condition is found in
(a)Petiole
(b)Leaves
(c)Stem
(d)Roots

Answer 1

Hint: Exarch is the setup in which towards the periphery, the protoxylem is directed, and towards the center, the metaxylem is directed. The centripetal pattern is followed in the development of the xylem in this arrangement.

Complete answer:
The exarch condition is found in roots.
The metaxylem is the closest to the center part of the root and the protoxylem is the nearest to the periphery. Exarch development is normally seen in the roots of vascular plants.

Additional Information: Among the two classifications of transport tissue in vascular plants, xylem is one and phloem is the other. The transport of water and nutrients from the roots of the plant to stems and leaves is the basic function of xylem.
Proto xylem is the first-formed xylem which developed from procambium and contains thin cells with wall thickenings which are annular, spiral, or scalariform.
Meta xylem is a part of the first xylem that differentiates later, after the formation of protoxylem which is distinguished usually by the broader tracheids and walls which are reticulated.
So, the correct answer is ‘Roots’.

Note: -Endarch is a condition that needs the growth of protoxylem from the interior procambial cells which are adjacent to the pith. The growth is inward to outward due to which the protoxylem is seen inside the metaxylem.
-The living tissue that is involved in the process of translocation, which is the transport of the soluble organic compounds formed by the process of photosynthesis which is called as the photosynthates.
-The word xylem is taken from the ancient Greek language, where ‘xylon’ means wood which is because the best xylem tissues are located in the woody part of vascular plants.