Identify the type of age pyramid for the human population shown in the image and state what it represents.

Death is important because it ......

$X$ - In deep-sea hydrothermal vents,the average temperature is between $25^{\circ}C$ to $30^{\circ}C$.
$Y$ - Reptiles and amphibians are eurythermal.

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.

Match the columns:

Column-$I$	Column-$II$
$(a)$ Earthworm	$(i)$ Birth-rate
$(b)$ Succession	$(ii)$ Pioneer species
$(c)$ Population rise	$(iii)$ Pollination
$(d)$ Ecological services	$(iv)$ Saprotrophs

Match the following and select the correct option.

$A.$ Earthworm	$(i)$ Pioneer species
$B.$ Succession	$(ii)$ Detritivore
$C.$ Ecosystem service	$(iii)$ Natality
$D.$ Population growth	$(iv)$ Pollination