The average natality rate in our village is $25$, the average mortality rate is $24$, immigration is $2$, and emigration is $3$. What is the net increase in the population?

$A$ population is:

Density of population increases when . . . . . . .

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 $ ......................$

Sex ratio is the

Some characteristics of the demography of developing countries are ....