原核生物細胞 (Prokaryotic cells )可分為細菌 (bacteria )和古菌 (archaea) 。原本細菌和古菌一起被分類在原核界裡，然而在較新的支序系統學(cladistic systems) 理，則利用基因序列 (gene sequencing) 的方法，將原核生物細胞劃分為兩界, 一界為真細菌 (或稱細菌) ，另一界為古菌 (以前又稱古細菌)。原核生物細胞本身没有細胞核，並且缺乏其他由膜結合成的細胞器。换句話說, 它們的生物結構非常的簡單， 根據化石研究結果證明，它們是地球上最早的生命起源。化石研究的資訊建議我们，最早期的單細胞，已經在35億年前開始進化了, 但是從沉積岩裡的碳同位素 (carbon isotopes) 研究顯示，生命(和細胞) 或許早在這之前的兩億年就開始了。
連結網頁
- 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.
連結網頁
- 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.