Transfer of Biomass + Energy

Why is biomass transfer between trophic levels inefficient?

Not all material is eaten, digested or incorporated into new biomass.

What happens to biomass that is not eaten?

It may remain as dead material or uneaten parts, entering decomposer food chains.

Why is some consumed biomass not transferred to the next trophic level?

Some material is egested as faeces or excreted as waste.

What is egestion?

The removal of undigested food from the digestive system.

What is excretion?

The removal of metabolic waste products from an organism.

Why is respiration important when explaining biomass transfer?

Organisms use organic molecules in respiration, so some biomass is not retained for growth.

What happens to carbon-containing biomass during respiration?

Some carbon is released as carbon dioxide.

Why does movement reduce the efficiency of biomass transfer?

Movement requires respiration, using energy from organic molecules.

Why does maintaining body temperature affect biomass transfer?

Endothermic animals use respiration to maintain body temperature.

What is biomass transfer efficiency?

The percentage of biomass at one trophic level transferred into biomass at the next.

How can biomass transfer efficiency be determined?

Biomass gained by the next trophic level ÷ biomass available at the previous level × 100.

What does a transfer efficiency of 10% mean?

10% of the biomass at one trophic level is transferred into the next.

Why is transfer efficiency often low?

Organisms respire, produce waste and leave some material uneaten.

Why are shorter food chains often more efficient for producing food?

They involve fewer inefficient biomass transfers.

Why is feeding crops directly to humans often more efficient than feeding crops to livestock first?

It avoids an additional trophic level and associated biomass losses.

Why do predators need to consume substantial amounts of prey?

Only a fraction of consumed biomass becomes new predator biomass.

What is the difference between energy transfer and biomass transfer?

Energy is transferred and dissipated, while biomass consists of organic material passed between organisms.

Why is it incorrect to say energy is recycled through a food chain?

Energy flows through ecosystems and is eventually dissipated to the surroundings.

Why can matter be recycled but energy cannot be recycled in the same way?

Matter is reused through nutrient cycles, while energy is transferred and dispersed.