Name: ______Period: ______Date: ______

WHO EATS WHOM?

Part 1: Vocabulary – Fill in the blanks with the terms below.

abiotic factors consumers ecology solar producers

biotic factors decomposers food chain food web trophic level

1.  ______All living factors in an ecosystem (plants, animals, etc.)

2.  ______All nonliving factors such as climate and temperature

3.  ______The study of how organisms interact with each other and the environment.

4.  ______Heterotrophic organisms that must consume other organisms for energy

5.  ______Describes plants because they make food from sunlight.

6.  ______Source of energy for most ecosystems on Earth.

7.  ______Organisms that obtain energy from the remains of other organisms.

8.  ______Feeding relationships between individual organisms

9.  ______Each step in a food chain or web that shows the feeding relationship between organisms

10. ______Mass of interconnecting food chains

Part 2: Food Chains and Food Webs

11. What is the initial (ultimate energy source of this ecosystem? ______

12. List all of the producers. ______

13. List all of the primary consumers. ______

14. List all of the secondary consumers. ______

15. List 1 food chain above that has 3 links. ______

16. List 1 food chain above that has 4 links. ______

17. Describe how 3 organisms would be affected if all of the mice were removed from the food web.

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18. Describe how the rabbit population would be affected if the mountain lions were removed from the food web.

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Part 3: Ecological Pyramids:

19.  Which trophic level contains autotrophic organisms? ______

20.  Which trophic level contains herbivores? ______

21.  Which trophic level contains carnivores and/or omnivores? ______

22.  Which trophic level contains the most available energy? ______

23.  Which trophic level contains the least available energy? ______

ORGANISM / NUMBERS / MASS / AVAILABLE ENERGY
Young human / 1 / 50 kg / .06%
cow / 4 / 1,000 kg / 7.00%
Alfalfa plant / 20 million / 8,000 kg / 100%

Fill in the pyramids using the information in the chart above, so that the three organisms are placed in their correct levels. Then, answer the questions that follow.

24.  What is the source of energy for all of the ecological pyramids? ______

25.  In general, what kind of organism makes up the base of any ecological pyramid? ______

26.  How is the energy loss from one trophic level to the next reflected in the pyramid of numbers? ______

27.  ______

28.  Suppose an ecosystem has a greater number of individual herbivores than individual producers. How would this affect the shape of the ecosystem’s pyramid of numbers? ______

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29.  In the pyramid of energy, why do different trophic levels have different amounts of energy available? ______

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