In a pond, there were $20$ lotus plants and $10$ new plants were added. Calculate the birth rate for the year.

The rate at which new born individuals are joining the population by reproduction is known as

The bio-index number means

Identify the odd one out from the given options regarding population attributes.

In the given diagram,identify $a, b, c,$ and $d$. Specifically,identify $b$ and $c$.

The density of a population in a habitat per unit area is measured in different units. Write the unit of measurement against the following:
$(a)$ Bacteria $.......................$
$(b)$ Banyan $ .......................$
$(c)$ Deer $ .......................$
$(d)$ Fish $ ......................$