Energy and ecosystems

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Question 1 of 48

0:003 parts · 5 marks

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A quantity of 8000 kJ of grain can be used in two ways to feed people. It can be eaten directly (as flour), or it can be fed to a bullock and the people eat the beef produced.

Fed to a bullock, the 8000 kJ of grain yields 480 kJ of beef.
Eaten directly, 6400 kJ of the grain reaches people as food.

(a)[2]
Calculate the percentage of the grain's energy that reaches people when it is fed to the bullock and eaten as beef.
(b)[2]
Using the data, explain why eating the grain directly provides more energy for people than eating beef produced from the grain.
(c)[1]
Suggest one reason why, despite this, some land is used to rear cattle rather than grow crops for people.