3. "...manufacturers engineer laboratory-patented GMO foods whose modified genetic code allows crops to survive heavy sprayings..." [Clue: altered DNA / biotech resistance]
4. "...companies formulate nearly every type of boxed processed food." [Clue: mechanically & chemically altered grain products]
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Prompt 1: Omnivore's Dilemma 2 Pts
Exemplar: Because omnivores have no built-in instinct telling them what is safe, they face the anxiety of deciding which foods are nourishing versus harmful. In modern markets, this dilemma centers on discerning which processed products are safe, ethical, and wholesome.
Award 2 pts: Mentions lack of specialized instinct and the difficulty of choosing what to eat.
Prompt 2: Subsidy & Bonanza 2 Pts
Exemplar: Government subsidies incentivize farmers to overproduce massive amounts of corn, causing raw prices to crash below production costs. This glut creates an economic bonanza for processors, who purchase ultra-cheap grain to manufacture lucrative food additives.
Award 2 pts: Connects taxpayer subsidies -> grain surplus -> corporate cheap inputs/profits.
Teacher Resource • The Omnivore's Dilemma Study Series Answer Key • Page 1 of 2
Teacher Answer Key
Part II Solutions: Cattle Biology, Feedlots & Meat Processing (Pollan, pp. 63–72)
Scoring Guide
Page 2 Total: 20 Points
Section 4 & 5 Answer Key:
1:evolved 2:ruminants 3:rumen 4:fermentation 5:forage 6:feedlots 7:acidosis 8:bloat 9:slaughterhouse 10:tallow
4
Cows are ancient grazing animals that [1] evolved over millions of years to digest tough grass cellulose that humans cannot eat. Because they chew cud and possess a multi-chambered stomach, cattle belong to a family of animals called [2] ruminants. Their first specialized chamber, the [3] rumen, functions like an internal fermentation vat where trillions of microbes break down fibers through [4] fermentation.
In natural pasture, cattle roam freely to [5] forage for grass. In factory farming, they are relocated to crowded, muddy [6] feedlots where they are fed an unnatural diet of calorie-dense grain. This causes dangerous metabolic [7] acidosis as body tissues become too acidic. Rapidly fermenting corn also traps fatal gas in their stomachs, causing [8] bloat. Once fattened, cattle are sent to a [9] slaughterhouse, where beef is cut and leftover fat is rendered into [10] tallow.
evolved
ruminants
rumen
fermentation
forage
feedlots
acidosis
bloat
slaughterhouse
tallow
5
Natural Pasture / Biological System 3 Pts
1. Forage Natural grazing behavior
2. Rumen Grass-digesting organ
3. Sustainable Closed-loop solar cycle
Industrial Corn / Confined Feedlot 3 Pts
1. Feedlots Crowded confinement pens
2. Acidosis High-starch metabolic illness
3. Bloat Fatal trapped gas from corn
6
Model Response A: Biological Focus
"Because cattle evolved as grass-eating ruminants, their digestive biology cannot tolerate starchy corn. Confining them in industrial feedlots induces severe acidosis, disrupting the natural ecological balance of farming."
Model Response B: Economic Focus
"Government subsidy policies create an unnatural surplus of cheap grain. Agribusiness herds cattle onto feedlots where corn induces deadly bloat, destroying what could otherwise be a sustainable food chain."
4 Points: 3 terms underlined and used with clear cause-and-effect reasoning.
2–3 Points: 3 terms used, but ecological connection or definition is slightly vague.
0–1 Point: Fewer than 3 terms used or incorrect application of biological concepts.
Teacher Resource • The Omnivore's Dilemma Study Series Answer Key • Page 2 of 2
