There are nine species of Impatiens (balsams) found in laterite plateaus of the northern Western Ghats, each with a distinct colour. If a plateau has exactly 6 species, then the number of possible colour combinations in the plateau is ….. (Answer in integer).
The figure illustrates the soil zinc tolerance of the grass species Anthoxanthum along a transect from inside a mine to the middle of a pasture outside the mine.
\includegraphics[width=0.5\linewidth]{62a.png}
Which one or more of the following processes explain(s) the observed pattern of zinc tolerance in this grass species?