How do roots of parasitic plants function?

The roots of parasitic plants are specialized structures that play a crucial role in their survival and growth. They attach to the host plant and penetrate its tissues, enabling the parasitic plant to access water, nutrients, and carbohydrates. This parasitic relationship means that the parasitic plant literally "steals" essential resources from the host plant to sustain itself, allowing it to thrive even in poor soil conditions where it might not be able to survive independently. This ability to draw from another plant's resources is what distinguishes parasitic plants from those that rely solely on photosynthesis and their own root systems.

The other options center on functions not associated with parasitic plants. For instance, while storing energy is a function of primary roots in many plants, parasitic plants don’t typically have a storage role due to their reliance on hosts. Producing seeds is a reproductive function that occurs after the plant matures, but it is not directly linked to the parasitic behavior of the roots. Lastly, photosynthesis is generally the process by which green plants make their food using sunlight, which parasitic plants often do not rely on due to their dependency on host plants; hence, their roots do not assist in this process.