Topic 5.7 Meat Production Methods: compare free-range and feedlot (CAFO) meat production and explain the environmental costs of meat, including its high resource use.

A 4-point FRQ on meat production.

(a) Explain (1 point): only about 10% of the energy in feed is converted into animal tissue (the 10% rule), so growing the grain to feed animals and then eating the animals wastes most of the energy; eating the grain directly would feed far more people on the same land.
(b) Describe (1 point): CAFOs concentrate huge amounts of manure that can run off and pollute water with nutrients and pathogens (and create odor and antibiotic-resistance concerns).
(c) Identify (1 point): methane (from cattle digestion) or nitrous oxide (from manure); carbon dioxide from associated energy use is also acceptable.
(d) Describe (1 point): free-range animals graze on pasture, spreading manure naturally, with lower concentrated pollution and often better animal welfare, though it uses more land.

Markers reward the 10% rule energy-loss argument, manure pollution for CAFOs, methane (or nitrous oxide) as a greenhouse gas, and a real free-range advantage.

A 1-point MCQ on meat production. The answer is (B).

Because only about 10% of energy passes from one trophic level to the next, feeding grain to animals and then eating the animals loses about 90% of the energy at that step; eating the plants directly avoids that loss, so the same land feeds more people. (A) is not the reason; (C) is false; (D) is irrelevant to energy efficiency. The trap is choosing a protein or spoilage explanation rather than the energy-transfer (10% rule) reason.