Plants growing on sandstone are known as:

Choose the correct sentences regarding biological nomenclature:
$(1)$ Biological names are generally in Latin and written in italics.
$(2)$ The first word in a biological name represents the genus while the second component denotes the specific epithet.
$(3)$ The genus name starts with a capital letter,while the specific epithet starts with a small letter.
$(4)$ The name of the author appears after the specific epithet in an abbreviated form.

Which of the following are unique characteristics observed in living organisms?

Study the four statements $(A-D)$ given below and select the two correct ones out of them.
$A.$ Definition of biological species was given by Ernst Mayr.
$B.$ Photoperiod does not affect reproduction in plants.
$C.$ Binomial nomenclature system was given by $R$.$H$. Whittaker.
$D.$ In unicellular organisms,reproduction is synonymous with growth.
The two correct statements are:

What is the essential requirement for a student of taxonomy?

About how much water is recycled in the form of rains per year?