Sex ratio in a species indicates the numerical relation between the number of
Male and female producing gametes
Blacks and whites
Unisexual and bisexual
None of the above
The population growth of India from $1981$ to $1991$ is
Secondary infertility is
‘Essay on population’ was published by
Castration cannot be taken as a contraceptive device, because
Which of the following can be taken as the most convincing factor for indicating the rapid increase in population growth of a country?