Parasitism is a biological relationship where one organism, the parasite, lives on or in another organism, the host, and benefits at the host's expense. In the case of the dodder plant, it is a parasitic vine that wraps around a host plant and attaches to it using specialized structures called haustoria. These haustoria penetrate the host's tissues and connect to its vascular system, allowing the dodder to extract water and nutrients from the host

. Dodder lacks chlorophyll and cannot photosynthesize, so once it attaches to a host, its own roots die and it becomes completely dependent on the host for survival

. This parasitic relationship weakens the host plant by robbing it of essential resources, making it more susceptible to diseases and pests, and reducing its growth and reproductive capacity

. Dodder can spread from one host plant to another, sometimes forming large masses that cover multiple plants

. In summary, parasitism involves the parasite benefiting by deriving nutrients and support from the host, which is harmed in the process. Dodder exemplifies this by physically attaching to and draining resources from other plants, often to their detriment.