The abundance of a species population within its habitat is called

The population of any species is:

Population is the total number of

If the age pyramid of a population is bell-shaped,it will show:

The type of population,where pre-reproductive animals occur in large numbers,is

Read the following statements and select the correct option with respect to population attributes:
$(a)$ Population density is necessarily measured in numbers.
$(b)$ Tiger census is often based on pug marks and fecal pellets.
$(c)$ Biomass is not a meaningful measure to know population size.
$(d)$ Size of a population for any species is not a static parameter.