39.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? A. Amensalism B. Commensalism C. Competition D. Predation
Option D Commensalism refers to relationship wherein one organism is benefitted while other remains unaffected and is denoted by + 0. Amensalism refers to association wherein one partner is inhibited while other remains nearly unaffected and is denoted by - 0. Association of organisms which benefits one of the partners at the expense of other is called as parasitism and is denoted by + -. Mutualism is association of organisms wherein both are benefitted and is denoted by + +.