Which of the following is an omnivore?

$A$: Population ecology is a link between ecology,population genetics,and evolution.
$R$: Natural selection operates at the population level to evolve desired traits.

Identify $X$ and $Y$ in the given figure,which represents the biome distribution with respect to mean annual temperature and mean annual precipitation.

Which process allows organisms to protect themselves during stressful environmental conditions?

Match the columns:

Column-$I$	Column-$II$
$(a)$ Cacti	$(i)$ Leguminous plants
$(b)$ Shade loving plants	$(ii)$ Commensalism
$(c)$ Halophytes	$(iii)$ Pioneer community
$(d)$ Crustose lichen	$(iv)$ Plants growing in saline environment
$(e)$ Interspecific interaction	$(v)$ Xerophytes
$(f)$ Rhizobium	$(vi)$ Sciophytes

The given human population age pyramid represents..........