If + sign is assigned to beneficial interaction, – sign to detrimental and 0 sign to neutral interaction, then the population interaction represented by + – refers to
parasitism
mutualism
amensalism
commensalism
Explanation:
Parasitism +, –
Mutualism +, +
Amensalism 0, –
Commensalism +, 0
Parasitism +, –
Mutualism +, +
Amensalism 0, –
Commensalism +, 0