Sousa, Nova (2012) Prokaryote organisms. Research World, Delhi, India. ISBN 9788132332077
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Abstract
The prokaryotes are a group of organisms that lack a cell nucleus (-karyon), or any other membrane-bound organelles. The organisms that have a cell nucleus are called eukaryotes. Most prokaryotes are unicellular, but a few such as myxobacteria have multicellular stages in their life cycles. The word prokaryote comes from the Greek xpó (pro-) "before" + kapoóv (karyon) "nut or kernel". It is generally agreed that prokaryotes as a group do not have taxonomic value. They understand two domains: the bacteria and the archaea. Archaea were recognized as a domain of life in 1990. These organisms were originally thought to live only in inhospitable conditions such as extremes of temperature, pH, and radiation but have since been found in all types of habitats. Prokaryotes are single-cell organisms that do not have a nucleus, mitochondria, or any other membrane-bound organelles. In other words, neither their DNA nor any of their other sites of metabolic activity are collected together in a discrete membrane-enclosed floating. Instead, everything is openly accessible within the cell, some of which is free. A distinction between prokaryotes and eukaryotes (meaning true kernel, also spelled "eucaryotes") is that eukaryotes do have "true" nuclei containing their DNA Unlike prokaryotes, eukaryotic organisms may be unicellular, as in amoebae, or multicellular, as in plants and animals. The difference between the structure of prokaryotes and eukaryotes is so great that it is sometimes considered to be the most important distinction among groups of organisms
| Item Type: | Book |
|---|---|
| Subjects: | Q Science > QH Natural history > QH301 Biology |
| Divisions: | Electronic Books |
| Depositing User: | Esam @ Hisham Muhammad |
| Date Deposited: | 12 Feb 2023 06:46 |
| Last Modified: | 12 Feb 2023 06:46 |
| URI: | http://odlsystem2.utm.my/id/eprint/3965 |
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