Question

A field of corn contains a certain amount of food energy. Compare the following situations and then answer the questions. Use the hypothetical examples below to help you.

corn human
corn cow human

In the corn human food chain, how does the amount of energy in the corn compare with the amount of energy consumed by the human beings?
In the corn cow human food chain, how does the amount of energy in the corn compare with the amount of energy consumed by the humans?
Do you think it is more efficient for humans to feed on corn or on beef?

Answer 1

plato answer

Step-by-step explanation:

In the corn human food chain, corn is a primary producer and humans are a primary consumer. Humans will receive roughly 10 percent of the energy of the corn. Supposing that corn has 1000 kcal/kg of energy, the amount of energy humans will receive is only 100kcal/kg.

In the corn cow human food chain, corn is a primary producer, cows are primary consumers and human are secondary consumers. Cows will receive about 10 percent of the energy of the corn, and humans in turn will receive about 10 percent of the energy of the corn from the cows.

In the corn human food chain, humans received 100kcal/kg energy (1000kcal/kg in corn 100kcal/kg in humans).

In the corn cow human food chain, humans received 10kcal/kg energy from the cows that fed on the corn (1000kcal/kg in corn 100kcal/kg in cows 10kcal/kg in humans).

Therefore, humans consume 10 times more energy from eating the corn directly than from eating beef from cows which fed on the corn. Thus, it is more efficient for humans to feed on corn directly rather than on beef.

Answer 2

Before assessing the two given cases, an assumption needs to be made about the digestion of the two types of food items, corn and beef. Let us assume that both get digested by expending same amount of energy by the human body. Let the amount of energy at producer level be an arbitrary X.

Case 1: Corn to human:

Since corn is at the producer level, it will have X amount of energy. The transfer of energy from corn to human will take place with a loss of 90% energy at the producer level. Hence the humans will receive 10% of X amount of energy.

Case 2: Corn to cow to human:

Since corn has X amount of energy, only 10% will pass to the next level, i.e. cow. So cow has 10% of X. Cow transfers only 10% of the energy that it has. Hence humans receive only 10% of 10% of X amount of energy.

It can be seen that humans receive more energy in case 1 than case 2. Hence we can say that it is more efficient for humans to feed on corn.