Example of a biodegradable polymer pair is

Thorn is a modified branch because:

The layer of cells outside the phloem meant for giving rise to the root branches is called

Plants adapted to low light intensity have

What is the quarantine regulation associated with?

$A$ point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$ are at distances of $2 \ m$ and $3 \ m$ respectively from the source. The ratio of the intensities of the waves at $P$ and $Q$ is