What type of organisms do protists include?

Protists are a diverse group of organisms that primarily consist of unicellular and simple multicellular forms. They are characterized by their ability to be eukaryotic, meaning they have cells with a nucleus and membrane-bound organelles. Algae, which can be both unicellular and multicellular, fall under the category of protists, making them crucial for various ecosystems as primary producers. Amoebas are also protists, known for their flexibility and ability to move via pseudopodia.

In this context, focusing on algae and amoebas accurately identifies two significant representatives of protists. This group encompasses a wide variety of life forms, including those that carry out photosynthesis and those that are heterotrophic, thus showcasing the diversity you would expect within the protist kingdom. The other suggestions mention categories that do not align with the characteristics of protists, such as lichens (a symbiotic relationship between fungi and algae) or mycorrhizae (a mutualistic association between fungi and plant roots), as well as defining plants and fungi, which belong to separate kingdoms in the classification system.