Editing Chloroplast (section)

=== Distribution in a plant ===

Not all cells in a multicellular plant contain chloroplasts. All green parts of a plant contain chloroplasts as the color comes from the [[chlorophyll]].<ref name="Campbell-2009g" /> The [[plant cells]] which contain chloroplasts are usually [[parenchyma]] cells, though chloroplasts can also be found in [[collenchyma]] tissue.<ref>{{cite book |last=Roberts |first=Keith |url=https://books.google.com/books?id=ucilIjrex5cC&pg=PA16 |title=Handbook of plant science |publisher=Wiley |year=2007 |isbn=978-0-470-05723-0 |location=Chichester, West Sussex, England |page=16 |name-list-style=vanc}}</ref> A plant cell which contains chloroplasts is known as a [[chlorenchyma]] cell. A typical [[chlorenchyma]] cell of a land plant contains about 10 to 100 chloroplasts.

In some plants such as [[cacti]], chloroplasts are found in the [[Plant stem|stems]],<ref>{{cite book |title=Biology |vauthors=Campbell NA, Reece JB, Urry LA, Cain ML, Wasserman, Minorsky PV, Jackson RB |publisher=Benjamin Cummings (Pearson) |year=2009 |isbn=978-0-8053-6844-4 |edition=8th |page=742}}</ref> though in most plants, chloroplasts are concentrated in the [[leaves]]. One square [[millimeter]] of leaf tissue can contain half a million chloroplasts.<ref name="Campbell-2009g" /> Within a leaf, chloroplasts are mainly found in the [[Mesophyll cell|mesophyll]] layers of a [[leaf]], and the [[guard cells]] of [[stomata]]. [[Palisade mesophyll]] cells can contain 30–70 chloroplasts per cell, while stomatal guard cells contain only around 8–15 per cell, as well as much less [[chlorophyll]]. Chloroplasts can also be found in the [[bundle sheath]] cells of a leaf, especially in [[C4 plants|C{{sub|4}} plants]], which carry out the [[Calvin cycle]] in their bundle sheath cells. They are often absent from the [[Epidermis (botany)|epidermis]] of a leaf.<ref name="Lawson" />