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

Read the given statements and identify the correct and incorrect ones.
$(1)$ The exponential growth curve can be calculated using the formula $N_t = N_0 e^{rt}$.
$(2)$ Bamboo and salmon fish show the production of offspring only once during their entire lifespan.
$(3)$ In the amensalism type of interaction,one species is harmed and the other species receives no benefit or harm.
$(4)$ $A$ competitively superior species eliminates the inferior species in a habitat.

What type of human population is represented by the given age pyramid?

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

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