Classification and identification of living organisms are not necessary for which of the following?

Select the correct pair from the following.

Match the names of branches of biology listed under column $I$ with the field of study given under column $II$; choose the answer which gives the correct combination of the alphabets of the two columns.
Column $I$ (Branch of biology) | Column $II$ (Field of study)
$A$ Palynology | $p$ Silkworms
$B$ Oncology | $q$ Pollens
$C$ Phycology | $r$ Cancer
$D$ Sericulture | $s$ Algae

Plants growing on sandstone are known as:

Which statement is correct regarding the study of the classification of organisms?

In which language does the term '$des$' mean 'away' or 'apart'?