$A$ country with a high rate of population growth took measures to reduce it. The figure below shows age-sex pyramids of populations $A$ and $B$ twenty years apart. Select the correct interpretation about them.

The given diagram represents the response of organisms to abiotic factors. What do $i, ii,$ and $iii$ represent respectively?
| $i$ | $ii$ | $iii$ |

Consider the following statements $(A-D)$ each with one or two blanks.
$(A)$ Bears go into $ . . . . . . (1) . . . . . . $ during winter to $ . . . . . . (2) . . . . . . $ cold weather.
$(B)$ $A$ conical age pyramid with a broad base represents $ . . . . . . (3) . . . . . . $ human population.
$(C)$ $A$ wasp pollinating a fig flower is an example of $ . . . . . . (4) . . . . . . $.
$(D)$ An area with high levels of species richness is known as $ . . . . . . (5) . . . . . . $.
Which one of the following options gives the correct fill-ups for the respective blank numbers from $(1)$ to $(5)$ in the statements?

Which of the following statements is correct?
$I.$ In a population,birth rate and death rate refer to per capita births and deaths,respectively.
$II.$ In nature,we rarely find isolated single individuals of any species.
$III.$ The size of a population for any species is a stable phenomenon.
$IV.$ Ecological effects of any factors on population growth are generally reflected in its size/population density.

According to the $1991$ census,the maximum percentage of population increase was in which state?

Which of the following phenomena does not play a significant role in the maintenance of homeostasis in an ecosystem?