What are sieve cells and sieve tubes?
The main difference between sieve cells and sieve tubes is that sieve cells are long cells with narrow pores whereas sieve tubes are shorter cells with wide pores. Sieve cells are the main conducting elements of the phloem in lower plants while sieve tubes are present in the phloem of angiosperms.
What is sieve cells in phloem?
SIEVE ELEMENTS (OF PHLOEM) Sieve elements are specialized cells that function in the conduction of sugars. They are typically associated with parenchyma and often some sclerenchyma in a common tissue known as phloem (Gr. phloe, bark, after the location of secondary phloem in the inner bark).
Are sieve cells and sieve tubes same?
The two types of sieve elements, sieve tube members and sieve cells, have different structures. Sieve tube members are shorter and wider with greater area for nutrient transport while sieve cells tend to be longer and narrower with smaller area for nutrient transport.
What is the function of sieve tubes in phloem?
The main function of the sieve tube is the transport of carbohydrates, primarily sucrose, in the plant. The interface of the tubes contains pores which help in conduction. Each sieve tube element is normally associated with one or more nucleated companion cells, to which they are connected by plasmodesmata.
Why are phloem vessels called sieve tubes?
Plant Physiology and Development Phloem contains specialized cell types. Sieve elements are long cells with restricted protoplasm and end walls penetrated by large pores. They are arranged vertically in series to form sieve tubes that allow the movement of water and assimilates with low resistance.
Why is it called sieve tube elements?
…in the phloem are called sieve elements and consist of sieve cells and sieve-tube members, the latter differing in having some sieve areas specialized into sieve plates (generally on the end walls). Sieve-tube members are arranged end to end to form sieve tubes, a name derived from the sievelike end…
What are sieve tubes explain?
Definition of sieve tube : a tube consisting of an end-to-end series of thin-walled living plant cells characteristic of the phloem and held to function chiefly in translocation of organic solutes.
Why are the sieve tube cells called so?
Sieve cells are also associated with gymnosperms because they lack thecompanion cell and sieve member complexes that angiosperms have. Their narrow pores are necessary in their function in most seedless vascular plants and gymnosperms which lack sieve-tube members and only have sieve cells to transport molecules.
Where are sieve tubes found?
phloem
Sieve tubes are found in the phloem vascular tissue. Sieve tubes are located in vascular plants that flower called angiosperms.
What are the sieve tubes made of?
Sieve tubes consist of sieve elements which are elongated cells, connected to each other via sieve plates to form a continous tube system that spreads out through the entire plant.
Why sieve tubes are Sclerenchyma cells?
A sieve-tube element is a specialized type of sclerenchyma. However, unlike the phloem sclerenchyma cells that have lignified cell walls (and therefore are more associated with providing support), the sieve-tube elements are not lignified. The sieve-tube elements have primary cells walls only.
What is the other name of sieve tube?
Sieve tube element In plant anatomy, sieve tube elements, also called sieve tube members, are a specialised type of elongated cell in the phloem tissue of flowering plants. Each companion cell is derived from the same mother cell as its associated sieve tube member.