Which of the following statements are correct?
1. In fresh water the average concentration of dissolved oxygen is 0.0010 per cent by weight.
2. Oxygen enters the aquatic ecosystem through the air water interface and by the photosynthetic activities of aquatic plants.
Select the correct option from the codes given below:

[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 & 2

1. To understand how energycould be flowing in this aquatic ecosystem, list the differentautotrophic and heterotrophic organisms found at each pond, andexplain its role in energy flow through the system.

2. How would the pH anddissolved oxygen change over the course of a day (morning, noon,and night)? Over the course of a year? What is driving thesechanges?

3.Levels of organic wastes from manmade sources such asfood-processing plants, run-off from the lawn, and wastewatertreatment bring a lot of organic material to the aquatic ecosystemsfavoring the oxidation of organic compounds. What would happen tothe dissolved oxygen and pH in the ponds or lakes if a large amountof wastewater is added to these systems?

4. What ecosystem goodsand services does each of the ponds you sampled today provide FIUas an institution? Do any of them benefit you personally? Name oneother Florida ecosystem and describe 2 goods or services itprovides the south Florida population.

Carbon dioxide is a limiting resource for most aquatic plants,even though it can reach quite high concentrations in surfacewaters. How is that possible?

Plants deplete the water immediately surrounding their leaves,creating a low-CO2 boundary layer.

It's bound up in bicarbonate, which plants cannot use.

Lakes and oceans are too acidic for most aquatic plants tofunction.

Plants prefer to use bicarbonate for photosynthesis, so CO2 isnot used.

Which abiotic factor is necessary for animals to survive in an aquatic ecosystem?

◯ A. Algal blooms

◯ B. Low salinity

◯ C. Dissolved  

◯ D. Dissolved  

◯ E. Light