A group of amoeboid and flagellate EUKARYOTES in the supergroup RHIZARIA. They feed by means of threadlike pseudopods.

One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.

A phylum of EUKARYOTES in the RHIZARIA group. They are small endoparasites of marine invertebrates. Spores are structurally complex but without polar filaments or tubes.

Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.

Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.

The relationships of groups of organisms as reflected by their genetic makeup.

DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.