11. Suggest reasons why the information represented in the pyramid of numbers of animals of one of the ecosystems you studied may not truly represent that ecosystem.
The information represented in the pyramid of numbers of animals of one of an ecosystem may not truly represent that ecosystem because it provide information only on the quantity of organic matter available at a particular time but not on the productivity and turnover time.
Post Merge: 12 years ago
12. According to your data, what is the ratio of third-order consumers to producers? Explain your answer.
Specific results may vary; however, the ratio of third-orders consumers to producers will very low. In other words, students should see many times the number of producers.
Post Merge: 12 years ago
13. Compare and contrast two of the ecosystems you studied. How is the energy conversion efficiency similar or different?
The amount of biomass decreases drastically from one trophic level to the next one as the flow of energy is a directed process and as an optimal ten percent of the biomass of the previous tropic level can be used in the next higher one. As a consequence, four, at the most five trophic levels exist in nature. The biomass of the sum of all carnivores is always smaller than that of the herbivores, and that of the herbivores again is smaller than that of the plants
Post Merge: 12 years ago
14. Does the population size increase or decrease at higher trophic levels in the pyramid of numbers of an ecosystem consisting of a tree, insects (that are herbivores) and birds feeding on the insects? Explain your answer.
As with the pyramid illustration, living things at the bottom of the pyramid such as trees exist in higher numbers than living things such as birds and insects higher in the pyramid. This decrease in biomass coincides with a decrease in energy conversion. Less energy at the top equates to less food for animals in that zone.
15. What might happen to an ecological pyramid of numbers in a forest ecosystem if most of the deer were killed due to hunting by people and disease?
The removal of deer would coincide with a reduction in alternative food sources for the predator of deer. It would also affect predator populations. Plants used by 4 deer for food would be expected to increase ultimately affecting the balance of the entire pyramid. Eventually, the pyramid would find a new balance or a new normal.
16. What would happen to an ecosystem if the decomposers disappeared?
Decomposers break down dead animals and plants. The reduction of these important living things would affect the entire ecosystem as living things like plants that rely on nitrogen in soil created by decomposers are reduced and as a result all living things existing above them are also adversely affected as biomass and the energy conversion is reduced.
17. Could there be a food chain without herbivores and carnivores?
Yes, as one existed early in the Earths history.
Post Merge: 12 years ago
1. The ultimate source of energy for most ecosystems is: a. Carbon b. Oxygen c. Sunlight* d. Water (Worth 5 possible points)
2. Organisms that directly use energy from the sun to make their own food are called: a. Autotrophs* b. Hetertrophs c. Carnivores d. Decomposers (Worth 5 possible points)
3. Which of the following illustrates the correct ordering of trophic levels? a. Decomposerscarnivoresautotrop
hsherbivores b. Herbivoresautotrophscarnivore
sdecomposers c. Autotrophsherbivorescarnivore
sdecomposers* d. None of the above (Worth 5 possible points)
4. Within an ecosystem: a. Energy flows in one direction only and nutrients are recycled* b. Energy is recycled and nutrients flow in one direction only c. Energy and nutrients flow in one direction only d. Energy and nutrients are both recycled 2 (Worth 5 possible points)
5. The efficiency of energy transfer from a lower trophic level to the next highest level is roughly: a. 1% b. 5% c. 10%* d. 50% e. 80% (Worth 5 possible points)
6. In aquatic ecosystems, biomass is least at which trophic level? a. Autotrophs* b. Herbivores c. Carnivores (Worth 5 possible points)
7. You are in an area where there are squid, seals and penguins. You are most likely in which ecosystem? a. Deciduous forest b. Desert c. Hot Antarctic Ocean Shore* d. Grassland (Worth 5 possible points)
8. You find yourself in an area where there are snakes, hawks and coyotes. Based upon these animal populations, you are most likely in which ecosystem? a. Deciduous forest b. Hot Desert c. Grassland d. You cannot tell from this information* (Worth 5 possible points)
9. You are in an area where the ground is littered with what appear to be dry, dead leaves. You are most likely in which ecosystem? a. Deciduous forest* b. Hot Desert c. Grassland d. You cannot tell from this information (Worth 5 possible points)
10. This zone has the greatest concentration of plankton in a freshwater lake ecosystem: a. Profundal b. Littoral c. Limnetic* 3 (Worth 5 possible points)
11. Suggest reasons why the information represented in the pyramid of numbers of animals of one of the ecosystems you studied may not truly represent that ecosystem. (Worth 5 possible points) Ecosystems may vary depending on environmental conditions. For example, in the winter you may see less plant life and a higher abundance of animals.
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