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?

Which of the following mechanisms helps organisms protect themselves from predators?

Which of the following is most commonly cited as a predator?

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

Mycorrhiza is an example of which of the following?

American lakes visiting flamingoes and resident fishes compete for their common food $A$ in the lake. Resources $B$ limiting for competition to occur; in interference competition,the feeding efficiency of one species might be $C$ due to the interfering and inhibitory presence of the other species,even if resources (food and space) are abundant. Choose the correct option for $A$,$B$,and $C$.