Food web illustrating ecological relationships among different organisms in an ecosystem.

Final Answer:
a) Land plants and tiny water plants
b) Slug, frog, heron
c) Tiny water plants → water fleas → diving beetle → small fish → perch → heron
d) Water fleas, diving beetles
e) Heron, perch
f) If frogs died out, the population of insects, diving beetles, and slugs would increase, while foxes and herons would have one less food source to survive on.
4) Food chains are linear; food webs are a group of food chains. Food webs are more useful because they provide different organisms with more than one food source to survive.

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