Question

Define :
a) ecosystem services
b) sere
c) BOD

Answer 1

a) Ecosystem services are the benefits gained by humans from the natural environment or from a healthy ecosystem.

b) Sere is an intermediate stage of ecological succession moving towards the climax community.

c) BOD is biological or biochemical oxygen demand which is the dissolved oxygen in the water sample which is required for aerobic respiration for the organic material breakdown.