Explanation:
19. The Habitat consists of a single species, the zone around the plant is free from most organisms, surrounded by weak or sickly plants.
20. Uniform distribution of single species since growth of other species would be inhibited. The single species would also be distributed from each other in equal or clumped intervals
21. No competition as all the surrounding plants have been inhibited. They can maximize use of all the nutrients effectively from the soil.
22. The other plants would be inhibited and there would be a loss of bio-diversity around the plant. There would be a growth of a single species.
23. Evolution only occurs due to competition and scarse resources. Because of allelopathy there is no competition so it would be unlikely that the species would evolve over time.
24. This can be used to suppress the growth of unwanted plants like weeds etc.