Which of the following pairs of organisms must eat other organisms for food? A. snake and human B. pig and apple tree C. ant and rose bush D. bear and cactus

To determine which pairs of organisms must eat other organisms for food, we need to assess their diets.

1. Snake and Human (A): Both snakes and humans are heterotrophs, which means they consume other organisms. Snakes eat animals, while humans eat various food sources, including plants and animals.

2. Pig and Apple Tree (B): Pigs are omnivores and must eat other organisms, while an apple tree is a producer that makes its own food through photosynthesis. Therefore, this pair includes one organism that does eat others (pig) and one that does not (apple tree).

3. Ant and Rose Bush (C): Ants are also heterotrophs and must consume food sources from other organisms. A rose bush, like the apple tree, is a producer that creates its own food through photosynthesis. Hence, this pair includes one consumer (ant) and one producer (rose bush).

4. Bear and Cactus (D): Bears are omnivores and must eat other organisms, while a cactus is a producer that gets its energy from sunlight. So, similar to the previous pairs, there is one consumer (bear) and one producer (cactus).

Conclusion

The pairs of organisms that must eat other organisms for food are primarily A (snake and human), B (pig and apple tree), C (ant and rose bush), and D (bear and cactus) all point to the fact that at least one organism in each pair consumes other organisms. However, if we are looking for the pair that solely relies on eating other organisms, the answer would be A (snake and human) and B (pig) as both are direct consumers.