# In the food chain, the transition of energy from the first trophic level to the second is 15%, and from the second to the third

**In the food chain, the transition of energy from the first trophic level to the second is 15%, and from the second to the third – 10%. Calculate the increase in biomass (kg) at the third trophic level, if the first trophic level has accumulated 3 x 10 ^ 4 kJ of energy. 1 kg of biomass at the third trophic level stores 45 kJ of energy**

1) Let’s make a diagram of the food chain:

Trophic level I – »Trophic level II -> Trophic level III.

2) Let’s calculate how much energy will go from trophic level I to level II:

3 • 10 ^ 4 kJ – 100% x kJ – 15% x = 4500 kJ.

3) Let’s calculate how much energy will pass from the II trophic level to the III level:

4500 kJ – 100% x kJ – 10% x = 450 kJ.

4) Let’s calculate the growth of biomass at trophic level III, if 1 kg of biomass contains 45 kJ of energy:

450 kJ: 45 kJ = 10 kg.

Answer’. 10 kg.