Match the columns:

Column-$I$	Column-$II$
$(a)$ Predation	$(i)$ Cuscuta and hedge plant
$(b)$ Commensalism	$(ii)$ Balanus and Chathamalus
$(c)$ Parasitism	$(iii)$ Cactus and Moth
$(d)$ Competition	$(iv)$ Orchid and Mango

$A$ high density of elephant population in an area can result in

Select the correct option for the following organisms:
$I -$ Copepods,$II -$ Liver fluke,$III -$ Lice,$IV -$ Ticks,$V -$ Ascaris,$VI -$ Cuscuta
Ectoparasites $\quad\quad$ Endoparasites

While explaining interspecific interaction of population,$(+)$ sign is assigned for beneficial interaction,$(-)$ sign is assigned for detrimental interaction and $(0)$ for neutral interaction. Which of the following interactions can be assigned $(+)$ for one species and $(-)$ for another species involved in the interaction?

Level of competition between species depends on
$I.$ availability of resources
$II.$ population density
$III.$ group interaction of organisms
Choose the correct combination

Copepods are . . . . . . .