Final answer:
Carnivorous plants, like the Venus flytrap, capture insects to supplement their nitrogen intake, necessary for protein synthesis, due to the nutrient-poor soils they inhabit. The correct answer is C. nitrogen ... to make protein.
Step-by-step explanation:
By trapping insects, carnivorous plants obtain nitrogen, which they need to make protein. This is because they often grow in environments like bogs and marshes where the soil is poor in nutrients such as nitrogen and phosphorus. Unlike heterotrophs which gain nutrients and energy from consuming other organisms, autotrophs, including carnivorous plants, make their own energy through photosynthesis.
However, the poor soil conditions make it difficult for these plants to obtain the necessary nitrogen for protein synthesis, which is crucial for their growth and survival. Therefore, these specialized plants have evolved insect-trapping mechanisms to supplement their nutrient intake. The correct answer is C. nitrogen ... to make protein.