Question

Consider the following statements regarding oxygen in the aquatic system:


1. The concentration of oxygen in the aquatic system is higher than that on the terrestrial ecosystems

2. The amount of dissolved oxygen present in water is infl uenced by temperature.


Which of the above statements is/are incorrect?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2​

Answer 1

Option A - 1 Only

More Information

☆ Dissolved Oxygen in Aquatic Ecosystems :-

• In aquatic ecosystems, oxygen is dissolved in water, where its concentration varies constantly depending on factors that influence the input and output of oxygen in the water.

• In freshwater, the average concentration of dissolved oxygen is 0.0010 percent (also expressed as 10 parts per million or 10 ppm) by weight, which is 150 times lower than the concentration of oxygen in an equivalent volume of air. Thus, the concentration of oxygen is less in the aquatic ecosystems than that in the terrestrial ecosystems.

• Oxygen enters the aquatic ecosystem through the air-water interface and by the photosynthetic activities of aquatic plants.

• Therefore, the quantity of dissolved oxygen present in an ecosystem depends on the rate at which the aforesaid two processes occur.

• Dissolved oxygen escapes the water body through the air-water interface and through respiration of organisms (fish, decomposers, zooplanktons, etc).

• The amount of dissolved oxygen retained in water is also influenced by temperature. Oxygen is less soluble in warm water. Warm water also enhances decomposer activity. Therefore, increasing the temperature of a water body increases the rate at which oxygen is depleted from water.

• When the dissolved oxygen level falls below 3-5 ppm, many aquatic organisms are likely to die.

________

Thank you

Answer 2

i think answer is Option A