Question

In the following food chain, \[10\] joules of energy are available to the hawk. How much energy does the plant have?
Plant 🡪 Rat 🡪 Snake 🡪 Hawk.

Answer 1

Hint: In a food chain the energy is transferred along from one trophic level to the next. But, the amount of energy available gets decreased from one trophic level to the other. In a food chain, only around \[10\] percent of the total energy is passed on to the next trophic level. The biomass gets smaller as less energy is transferred at each level of the food chain.

Complete answer:
A food chain is a linear sequence of creatures through which nutrients and energy passed on as one organism feeds another. Each organism occupies a different trophic level in a food chain and is defined by how many energy transfers separate it from the basic input of the chain.
When one organism eats another, energy gets transferred between trophic levels and obtains the energy rich molecules from its prey’s body. These energy transfers are inefficient and it limits the length of food chains. Some of the energy is stored as biomass as part of organisms’ bodies when energy enters a trophic level. This is the available energy for the next trophic level since only the energy stored as biomass can get eaten. Only about \[10\% \] of the energy that’s stored as biomass in one trophic level per unit time ends up stored as biomass at the next trophic level per the same unit time, as a rule of thumb. This is the \[10\% \] rule of energy transfer.
Here, it is given that 10 joules of energy are available to the hawk. So according to the \[10\% \] rule of energy transfer across the trophic level, the snake will have about \[100\] joules, rats will have about \[1000\] joules and plants will have about \[10000\] joules.

Therefore, \[10000\] joules is the correct answer.

Note:
For the survival of most species, food chains are important. It can result in extinction of a species in some cases when only one element is removed from the food chain. Primary producers are the foundation of the food chain. The primary producers, also called autotrophs, utilize energy which is derived either from sunlight or from inorganic chemical compounds and creates complex organic compounds.