原核生物细胞 (Prokaryotic cells )可分为细菌 (bacteria )和古菌 (archaea) 。原本细菌和古菌一起被分类在原核界里，然而在较新的支序系统学 (cladistic systems) 里则利用基因序列 (gene sequencing) 的方法将原核生物细胞划分为两界, 一界为真细菌 (或称细菌) ，另一界为古菌 (以前又称”古细菌”)。原核生物细胞本身没有细胞核并且缺乏其他由膜结合成的细胞器。换句话说, 它们的生物结构非常的简单， 根据化石研究结果证明它们是地球上最早的生命起源。化石研究的资讯建议我们，最早期的单细胞已经在35亿年前开始进化了, 但是从沉积岩里的碳同位素 (carbon isotopes) 研究显示，生命(和细胞) 或许早在这之前的两亿年就开始了。
网 页 连 结
- Thinkquest has a page about the Prokaryotic Cells.
- The University of the Western Cape (in Capetown, South Africa) has a good page about Cyanobacteria (one of the groups of prokaryotes).
- A page of notes on prokaryotes made by Michael Gregory.
- A very good page on the evolution of cells made by Thomas J. Herbert.
- The Bacteria Museum has a great page on the earliest bacteria.
网 页 连 结
- Thinkquest has a page about the Prokaryotic Cells.
- The University of the Western Cape (in Capetown, South Africa) has a good page about Cyanobacteria (one of the groups of prokaryotes).
- A page of notes on prokaryotes made by Michael Gregory.
- A very good page on the evolution of cells made by Thomas J. Herbert.
- The Bacteria Museum has a great page on the earliest bacteria.