In stems, the protoxylem lies towards the _____________ and the metaxylem lies towards the ____________ of the organ.

Correct Answer : A.

The first formed primary xylem elements are called protoxylem and the later formed primary xylem is called metaxylem. In stems, the protoxylem lies towards the centre (pith) and the metaxylem lies towards the periphery of the organ. This type of primary xylem is called endarch.