Death is important because it ......

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.

The figure given below is a diagrammatic representation of the response of organisms to abiotic factors. What do $a$,$b$,and $c$ represent respectively?

Comment on the following figures: $I, II$ and $III$. Here,$A, B, C, D, G, P, Q, R, S$ represent different species.

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?

Match the ecological hierarchy given in Column-$I$ with their explanation in Column-$II$. Choose the correct answer from options given below.

Column-$I$	Column-$II$
$a$. Organism	$i$. Flora and fauna of a specific climatic zone.
$b$. Population	$ii$. Populations of different species of an area.
$c$. Community	$iii$. Organisms of same kind inhabiting an area.
$d$. Biome	$iv$. Basic unit of hierarchy.