In which disorder change of single base pair in the gene for beta globin chain results in change of glutamic acid to valine ?
For chemical defence against herbivores, Calotropis has :
Consider the following tissues in the stelar region of a stem showing secondary growth.
(A) Primary xylem
(B) Secondary xylem
(C) Primary phloem
(D) Secondary phloem
Arrange these in the correct sequence of their position from pith towards corts.
Which of the following mineral ion is not remobilized in plants?