Question

carbon is exchanged within the biosphere when heterotrophs - organisms that consume other organisms for food - consume autotrophs or other heterotrophs. for example, when a cow eats grass, it consumes the carbon - based carbohydrates, lipids, and proteins that make up the grass. these molecules are broken down and rearranged in the cows cells during digestion. select the true statements. carbon moves within the biosphere when heterotrophs consume autotrophs. carbon - based molecules are broken down by heterotrophs as they digest food. carbon only moves from heterotrophs to autotrophs within the biosphere. heterotrophs only consume autotrophs, not other heterotrophs.

Explanation:

1. The text states that carbon is exchanged in the biosphere when heterotrophs consume autotrophs, so the first statement is true.
2. It also mentions that when a cow (a heterotroph) eats grass, carbon - based molecules in the grass are broken down during digestion, validating the second statement.
3. Carbon moves in multiple directions in the biosphere, not just from heterotrophs to autotrophs, so the third statement is false.
4. Heterotrophs can consume both autotrophs and other heterotrophs, so the fourth statement is false.

Answer:

1. Carbon moves within the biosphere when heterotrophs consume autotrophs.
2. Carbon - based molecules are broken down by heterotrophs as they digest food.