World environment day is celeberated on
$15^{th}$ March
$15^{th}$ April
$4^{th}$ May
$5^{th}$ June
Which one of the following scientists is famous for his contributions in ecological researches
Reproductive isolation between segments of a single population is termed as
Who defined ecology as the reciprocal relationship between organisms and their environments
The term ‘biocoenosis’ was proposed by
One of the effects of dust is to cause