Question

Which of the following units can be appropriately used in the expression of Primary Productivity of an ecosystem?

• A. g m²/yr
• B. Kg/Km²/yr
• C. g/yr
• D. g/m/yr

Hint:

Productivity = mass per unit area per unit time.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Productivity is the rate of biomass made per unit area per unit time. The unit must therefore be mass divided by area divided by time.

Step 2: Check option 1:
As printed, g m²/yr multiplies grams by area. That is not mass per area. It looks like a misprint of g m^-2 yr^-1, but as printed it is wrong.

Step 3: Check option 2:
Kg/Km²/yr is mass per area per year. It has the right form with bigger units, so it is appropriate. Correct.

Step 4: Check option 3:
g/yr has no area part. Wrong.

Step 5: Check option 4:
g/m/yr has length, not area. Wrong.

Step 6: Note:
Option 1 may have been meant as the passage unit, but its printed form is wrong. Option 2 is chosen as the dimensionally correct one.

Final Answer:
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