Biology help please! 10 points?

1. Compare the digestive systems of a flatworm and a human. Be sure to include examples of the various structures found in the digestive systems of both organisms.
2.Name the trophic levels in an ecosystem and explain how energy moves through the trophic levels. Use the terms food chain and food web in the discussion.
3. Describe two of the following environmental issues that confront modern society: global warming, air pollution, acid rain, and hazardous waste. Explain how the issues are problems for society and how scientific studies can inform people concerned with the issues.

Trophic levels are the feeding position in a food chain such as primary producers, herbivore, carnivore, etc. Plants are the first trophic level, the producers. Herbivores assemble the second trophic level. The carnivores form the third and the fourth trophic levels.


Food Chains is the chain of transfer of energy from one organism to another. Ex. Food Chain
Rose plant - aphids - beetle - chameleon - hawk.


In the example food chain, the rose plant is the primary producer. The aphids are the primary consumers because they suck the juice from the rose plant. The beetle is the primary carnivore because it eats the aphids. The chameleon, a secondary carnivore, the beetle. The hawk is the tertiary carnivore because it eats the secondary carnivore, the chameleon. The hawk eventually dies and its remains are broken down by decaying caused by bacteria and fungi.