The third domain Eukaryota includes all multicellular organisms and many unicellular protists and protozoans. Coccolithophores are minute unicellular photosynthetic protists with two flagella for locomotion. Microbiota includes bacteria, archaea, protists, fungi and viruses. Types of human microbiota include bacteria, archaea, fungi, protists and viruses. Eukaryotes are the more developed life forms known as plants, animals, fungi and protists. Bacteria, fungi, archaea, protists, and viruses are all members of the plant holobiont. Various forms of life exist, such as plants, animals, fungi, protists, archaea, and bacteria. Some protozoa are "photoautotrophic" protists. However, some unicellular protists and bacteria are macroscopic and visible to the naked eye. Some amoebae are predatory and live by consuming bacteria and other protists. Some single-celled marine protists are macroscopic. Many protists and fungi alternate between sexual and asexual reproduction. They have a wide host range, including vertebrates, invertebrates, plants, protists and fungi. Amoeba have generally been regarded as asexual protists. Nevertheless, the great majority of animals, plants, fungi and protists reproduce sexually.