Science / Biology / Prokaryote: Type of cell that lacks a membrane-bound nucleus and has no membrane organelles; a bacterium. Prokaryotes are more primitive than eukaryotes. Cells lacking membrane-bound organelles and having a single circular chromosome, and ribosomes surrounded by a cell membrane. Prokaryotes were the first forms of life on earth, evolving over 3.5 billion years ago.
Science / Genetics / Chromosome: The self-replicating genetic structure of cells containing the cellular dna that bears in its nucleotide sequence the linear array of genes. In prokaryotes, chromosomal dna is circular, and the entire MORE
Science / Biology / Eukaryote: A type of cell found in many organisms including single-celled protists and multicellular fungi, plants, and animals; characterized by a membrane-bounded nucleus and other membraneous organelles; an o MORE