Question

In a food chain _____ of biomass is transferred from one trophic level to the next trophic level.

• A. 20--30%
• B. 5--10%
• C. 30--40%
• D. 10--20%

Hint:

Lindeman's 10% law: \[ \text{Only about 10\% energy passes to next trophic level} \] This is why food chains are usually short.

Answer 1

The Correct Option is D

Concept:
Energy transfer in food chains follows the: \[ \boxed{\text{10\% Law}} \] proposed by Lindeman. According to this law: Only about \(10\%\) of energy or biomass is transferred from one trophic level to the next higher trophic level. The remaining energy is lost as:
• Heat
• Metabolic activities
• Respiration

Step 1: Understand trophic levels.
Examples:
• Producers
• Primary consumers
• Secondary consumers
• Tertiary consumers As we move upward in food chain: \[ \text{Available biomass decreases} \]

Step 2: Apply the 10% law.
Suppose plants contain: \[ 1000 \text{ units of energy} \] Then herbivores receive only: \[ 100 \text{ units} \] Carnivores receive: \[ 10 \text{ units} \] Thus only around: \[ 10\% \] is transferred between trophic levels.

Step 3: Analyze options carefully.
The closest range containing the standard value is: \[ 10-20\% \] Hence option (D) is correct according to given choices.

Step 4: Choose the correct answer.
Therefore, biomass transferred between trophic levels is approximately: \[ \boxed{10-20\%} \] Hence, \[ \boxed{(4)\ 10-20\%} \]