1. 21-WEEK ASSESSMENT REVIEW

2. One species benefits with no harm or affect on the other.
What is commensalism?
One species benefits with no harm or affect on the other.

3. What is mutualism? Both species benefit from the relationship.
Ex: an orchid being pollinated by a nectar collecting wasp

4. One species benefits at the expense of or harm to the other species.
What is parasitism?
One species benefits at the expense of or harm to the other species.
Ex: tick feeding on a dog; mistletoe absorbing nutrients from an ash tree

5. The fish can’t adapt or reproduce fast enough
Why is overfishing bad?
The fish can’t adapt or reproduce fast enough

6. What is the difference between these 2 pyramids?
The top pyramid, each level supports a lesser amount of biomass.
Bottom pyramid, less phytoplankton can support a larger amount of zooplankton.

7. Put the following on the pyramid in order of greatest biomass, or energy, or total number.
Grass
Wolf
Raccoon Grasshopper
Wolf
3rd Consumer
Raccoon
2nd Consumer
Grasshopper
1st Consumer
Producers
Grass

8. How much energy is passed to the next level?
10%

9. What happens to the other 90%?
Used by the organisms at that level & given off as heat

10. If there are 50,000 kilocalories of energy at the producer level in a habitat, how many kilocalories would be at the tertiary consumer level?
50 tertiary
500 secondary
5,000 primary
50,000 producer

11. What trophic level contains the most energy?
Primary Consumer
Tertiary Consumer
Producer
Secondary
Consumer
Producers

12. Rabbits and mice are herbivores that feed on grass
Rabbits and mice are herbivores that feed on grass. Cats are carnivores & prey on mice. Rabbits are prey to both cats & foxes. What would the food web look like for these feeding relationships?
Fox
Cat
Mouse
Rabbit
Grass

13. Fox
Cat
Mouse
Rabbit
Grass
Explain which animals would be affected if a disease killed out all the grass.
All would be affected because of lack of food.

14. The number of ants will decrease & the amount of grass will increase
In a habitat, horned toads eat ants and ants eat grass. What would happen if the number of horned toads increased?
The number of ants will decrease & the amount of grass will increase

15. Where do herbivores get their energy?
Producers

16. Which organisms are herbivores?
Snails, grasshopper, snow geese

17. Which organisms are carnivores?
Rat, salmon, bald eagle, marsh hawk, harbour seal, killer whale

18. Which organisms are omnivores?
Vole, Herring, mosquito

19. What trophic level of a food web would be the most damaging if it died out?
producers
Can you explain why?
All the energy in the system starts with the producers. All other levels would run out of food eventually.

20. Marsh vegetation (grasses)
The removal of which organisms would have the greatest affect on the ecosystem?
Marsh vegetation (grasses)

21. What happens to dead animal tissue in an ecosystem?
Becomes nutrients for other organisms

22. Bacteria fix the most nitrogen.
In the nitrogen cycle, what organisms that live in soil and on roots fix or make usable by plants the greatest amount of nitrogen?
Bacteria fix the most nitrogen.

23. The cycle will be disrupted and slowed
What would happen if decomposers like earthworms were removed from an ecosystem?
The cycle will be disrupted and slowed

24. What is primary succession?
Regrowth of a community on barren land where no life has inhabited before

25. Pseudomonas aeruginosa, a common bacteria, fights off competitors by injecting them with toxic proteins using a needle like puncturing device…
Good competitor

26. What are examples of primary succession?
Oceanic volcano eruptions & glacier retreats

27. What species would appear first during primary succession?
Lichens & mosses

28. What is secondary succession?
Regrowth of a community after a natural disaster
Ex: forest fire, hurricane, volcano eruption

29. What type of organisms would grow after soil had formed?
grasses