companion cell
Quick Summary
A companion cell is a living cell found in vascular plants that is closely associated with sieve tube elements in the phloem. These cells are produced from the same mother cell as the sieve element and share a close origin and position. Companion cells are essential for the function of sieve elements, which are responsible for transporting sugars from the leaves to other parts of the plant. While sieve elements lack a nucleus, companion cells possess one and carry out vital cellular functions for their adjacent sieve elements. They typically contain more mitochondria and ribosomes than other parenchyma cells. Companion cells are crucial for the transport of food throughout the plant and are believed to die when the sieve elements they support break down.123
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sieve elementā¦almost always adjacent to nucleus-containing companion cells, which have been produced as sister cells with the sieve element from the same mother cell. Companion cells apparently function with the enucleate sieve tube elements and die when they break down. The sieve cells of non-angiospermous vascular plants lack true companion cells,ā¦
Read Moreā¦almost always adjacent to nucleus-containing companion cells, which have been produced as sister cells with the sieve element from the same mother cell. Companion cells apparently function with the enucleate sieve tube elements and die when they break down. The sieve cells of non-angiospermous vascular plants lack true companion cells,ā¦
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angiospermOrganization of the vascular tissueā¦specialized parenchyma cell called a companion cell. They are derived by mitosis from the same parent cell and remain connected with each other. Photosynthates are actively secreted into, and actively removed from, sieve-tube members by their companion cells. Other unspecialized parenchyma cells also are present in primary phloem and provideā¦
Read Moreā¦specialized parenchyma cell called a companion cell. They are derived by mitosis from the same parent cell and remain connected with each other. Photosynthates are actively secreted into, and actively removed from, sieve-tube members by their companion cells. Other unspecialized parenchyma cells also are present in primary phloem and provideā¦
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magnoliid cladeVegetative structuresā¦angiosperms are sieve tubes and companion cells found in the phloem (see angiosperm: Vascular tissue). In other vascular plants, parenchyma cells function in the same way as companion cells (that is, as the sieve cellās living protoplasm), but they are not derived from the same mother cell as the sieveā¦
Read Moreā¦angiosperms are sieve tubes and companion cells found in the phloem (see angiosperm: Vascular tissue). In other vascular plants, parenchyma cells function in the same way as companion cells (that is, as the sieve cellās living protoplasm), but they are not derived from the same mother cell as the sieveā¦
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