Q5.5. As you saw in Section 2 ("DO or Die"), adding nutrients to a lake has direct effects (such as stimulating the growth of phytoplankton) and indirect effects throughout the community (such as drastic effects on fish populations). Suppose you triple (3x) the phosphorus input in a lake where phosphorus is limiting, and phytoplankton populations grow dramatically. Based on your observations, which of the following predictions is most likely to follow the phytoplankton bloom? Decomposition decreases, dissolved oxygen increases, and fish populations grow. Decomposition increases, dissolved oxygen decreases, and fish populations die off. Decomposition increases, dissolved oxygen decreases, and fish populations grow. Decomposition increases, dissolved oxygen increases, and fish populations die off.
Added by Marissa H.
Close
Step 1
This means there is more organic matter in the water for decomposition. So, decomposition would likely increase. Second, decomposition uses up oxygen. So, as decomposition increases, the amount of dissolved oxygen in the water would likely decrease. Show more…
Show all steps
Your feedback will help us improve your experience
Adi S and 53 other Biology educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
As you saw in Section 2 ("DO or Die"), fish are sometimes lost from lakes as eutrophication occurs. Given what you've learned in this lab about why these fish kills occur, which of the following might help prevent fish kills as phosphorus concentrations increase? Installing aerators that increase the oxygen concentration in the water Periodically adding more algae to the lake throughout the year Adding nitrogen to promote increased algal growth in the lake Trawling the lake with specialized nets to filter out extra zooplankton
Sri K.
In the Arctic Ocean, the predominant primary producers are phytoplankton. Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In years when there is more open water (less ice coverage), there are more zooplankton and fish than in years with less open water (more ice coverage). Based on the graph above, the difference is most likely because: A) When there is less open water, light is blocked from the zooplankton, so they cannot produce as much food for the fish. B) When there is more open water, the temperature is warmer, so the zooplankton and fish populations increase in size. C) The ice blocks the light, so in years with more ice coverage, there is less photosynthesis by the phytoplankton. D) The ice increases the light available for photosynthesis, so primary production increases and zooplankton populations increase in size.
Sukhwinder N.
Recommended Textbooks
Biology for AP Courses
Objective Biology for NEET
Introduction to General, Organic and Biochemistry
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD