The geometric representation of age structure is a characteristic of:

Under a particular set of selection pressure,organisms evolve towards the most efficient reproductive strategy. For example:
$A$) Oysters produce a large number of small-sized offspring.
$B$) Mammals produce a small number of large-sized offspring.
In the light of the above statements,choose the correct option.

The following diagrams represent the age pyramids of different populations. Comment on the status of these populations.

If the mean and the median pertaining to a certain character of a population are of the same value,the following is most likely to occur:

Under a particular set of selection pressure,organisms evolve towards the most $A$ reproductive strategy. Some organisms breed only $B$ in lifetime while others breed $C$ in lifetime. Choose the correct option for $A, B$ and $C$.

What effect does natality have on a population?