"Population is an auto-regulated system" was said by

Choose the wrong statement.

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.

If birth rate is $100,$ death rate is $10,$ and the number of individuals in the population group is $1000,$ then what will be the percentage of natural growth rate (in $, \%$)?

$(a)$ Label the three tiers $1, 2, 3$ given in the above age pyramid.
$(b)$ What type of population growth is represented by the above age pyramid?

$A$ group of individuals living in a particular geographical area at a particular time is called: