Answer: A
Explanation:
Because both introduce substance that harm organisms. All the other ones are wrong because<em> eutrophication</em> is a natural process that involes little to<em> no human interference . </em>
Worker bees eat the left over polin and nectar left by the honey bees.
Birds because they spread seeds
Answer:
Unlike matter, as energy flows through an ecosystem in one direction, from photosynthetic organisms to herbivores to omnivores and carnivores and decomposers, less and less energy becomes available to support life.
Explanation:
Primary producers use energy from the sun to produce their own food in the form of glucose, and then primary producers are eaten by primary consumers who are in turn eaten by secondary consumers, and so on, so that energy flows from one trophic level, or level of the food chain, to the next.
Energy is acquired by living things in three ways: photosynthesis, chemosynthesis, and the consumption and digestion of other living or previously-living organisms by heterotrophs.
Living organisms would not be able to assemble macromolecules (proteins, lipids, nucleic acids, and complex carbohydrates) from their monomeric subunits without a constant energy input.