Search results
Results from the WOW.Com Content Network
Chloroplasts, containing thylakoids, visible in the cells of Ptychostomum capillare, a type of moss. A chloroplast (/ ˈ k l ɔːr ə ˌ p l æ s t,-p l ɑː s t /) [1] [2] is a type of organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells.
Chloroplasts may contain 60–100 genes whereas cyanobacteria often have more than 1500 genes in their genome. [27] The parasitic Pilostyles have even lost their plastid genes for tRNA. [28] Contrarily, there are only a few known instances where genes have been transferred to the chloroplast from various donors, including bacteria. [29] [30] [31]
This image is a derivative work of the following images: File:Chloroplast-new.jpg licensed with PD-user-en, PD-user-w . 2005-11-26T06:46:29Z Ollin 748x501 (54894 Bytes) A person whose nickname is “It'sJustMe“ made this file in Microsoft Visio. the creator of this work, hereby release it into the public domain.
Therefore, chloroplasts may be photosynthetic bacteria that adapted to life inside plant cells. Like mitochondria, chloroplasts possess their own DNA, separate from the nuclear DNA of their plant host cells and the genes in this chloroplast DNA resemble those found in cyanobacteria. [70]
Like mitochondria, chloroplasts have a double-membrane envelope, called the chloroplast envelope, but unlike mitochondria, chloroplasts also have internal membrane structures called thylakoids. Furthermore, one or two additional membranes may enclose chloroplasts in organisms that underwent secondary endosymbiosis , such as the euglenids and ...
Euglena's chloroplasts are surrounded by three membranes, while those of plants and the green algae (among which earlier taxonomists often placed Euglena) have only two membranes. This fact has been taken as morphological evidence that Euglena's chloroplasts evolved from a eukaryotic green alga. [11]
Therefore, chloroplasts may be photosynthetic bacteria that adapted to life inside plant cells. Like mitochondria , chloroplasts still possess their own DNA, separate from the nuclear DNA of their plant host cells and the genes in this chloroplast DNA resemble those in cyanobacteria. [ 206 ]
Chloroplasts have their own genome, which encodes a number of thylakoid proteins. However, during the course of plastid evolution from their cyanobacterial endosymbiotic ancestors, extensive gene transfer from the chloroplast genome to the cell nucleus took place. This results in the four major thylakoid protein complexes being encoded in part ...