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Cells containing sieve plates are called sieve tube members, a component of the phloem, which carries sugars produced in the leaves to various parts of the plant. They are characteristic of angiosperms (flowering plants) while gymnosperms (cone-bearing plants) have only sieve cells. Sieve cells and sieve tube members are collectively referred to as sieve elements.
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How is sieve tube different from companion cells?
The sieve tube elements are specialized elongated cells in the phloem that connect end to end forming a tube. The main function of this tube is to transport nutrition in the form of carbohydrates. Sieve cells have no nucleus, ribosomes and cytoplasm, meanin they cannot carry out primary metabolic activities. The companion cells, which are closely associated with the sieve tube elements, carry out the their metabolic functions.
What are the four basic types of tissues in plants?
ProtectiveProtective tissue covers the surface of leaves and the living cells of roots and stems. Its cells are flattened with their top and bottom surfaces parallel. The upper and lower epidermis of the leaf are examples of protective tissue XylemXylem conducts water and dissolved minerals from the roots to all the other parts of the plant. PhloemThe main components of phloem are sieve elements andcompanion cells.Sieve elements are so-named because their end walls are perforated. This allows cytoplasmic connections between vertically-stacked cells. The result is a sieve tube that conducts the products of photosynthesis --- sugars and amino acids --- from the place where they are manufactured (a "source"), e.g leaves, to the places ("sinks") where they are consumed or stored; such asrootsgrowing tips of stems and leavesflowersfruits, tubers, corms, etc.Sieve elements have no nucleus and only a sparse collection of other organelles. They depend on the adjacent companion cells for many functions.Companion cells move sugars and amino acids into and out of the sieve elements. In "source" tissue, such as a leaf, the companion cells use transmembrane proteins to take up --- by active transport --- sugars and amino acids from the cells manufacturing them. Water follows by osmosis. These materials then move into adjacent sieve elements by diffusion through plasmodesmata. The pressure created by osmosis drives the flow of materials through the sieve tubes.In "sink" tissue, the sugars and amino acids leave the sieve tubes by diffusion through plasmodesmata connecting the sieve elements to the cells of their destination. Again, water follows by osmosis where it mayleave the plant by transpiration orincrease the volume of the cells ormove into the xylem for recycling through the plant.
Would you be able to separate jam and raisins using a sieve?
You can't sepertate jam with raisins with a sieve because jam is lumpy so it will not fall through the sieve. But raisins are too, the holes in a sieve are to small for a raisis to fit through.
When a group of cells that all have the same basic structure and function come together what do they form?
A group of cells with the same basic structure and function makes a tissue. Different tissues come together to make organs.
What is the difference between filter paper and a sieve?
filter paper is paper and a sieve is a kitchen utensil used to put objects (pasta,rice) and drain water.filter paper is used to seperate smaller granules (sand etc.) and a sieve is used to seperate larger granules(peas, rice, pasta etc.)
Function of phloem parenchyma?
The parenchyma cells in between the sieve tubes of the phloem, and functions primarily for food storage.
What is a sieve phloem?
The cells having sieve like perforations in their cell walls present in phloem are the sieve tubes of the phloem.
What are the dark rounded bodies inside phloem cells?
Sieve tubes
What is the sugar-transporting cells in angiosperms?
Tubes in the steam.
How do water- conducting cells differ from cells that transport food?
Xylem (water-conducting cells) are dead (no cytoplasm), and form long tubes called vessels (no end walls) The walls are thickened with ligninPhloem (food transport cells) are living (have cytoplasm) There are two cell types - sieve tubes which conduct the food - they have end walls with perforations (sieve plates) and have no nucleus and companion cells - they don't conduct food but have a nucleus and they support the sieve tubes
What is the shape of companion cells?
Irregular and sometimes spherical depending on their position between the sieve tubes.
What are sieve-tube cells?
In plant anatomy, sieve tube elements, are a specialized type of elongated cell in the phloem tissue of flowering plants. The ends of these cells connect with other sieve tube members, making up the sieve tube, whose main function is transport of carbohydrates in the plant.
What is the function of companion cells?
it protect the phloem part i.e. it seive tube the companian cell provide the protein ,ATP,air ,light which help in the devlopment of sieve tubes .
What are constituents of phloem?
i) Sieve tubes (ii) Companion cells (iii) Phloem parenchyma (iv) Phloem fibres
What are the constituents of phloem?
i) Sieve tubes (ii) Companion cells (iii) Phloem parenchyma (iv) Phloem fibres
Are used for what in a sieve which size plates?
Sieve plates are cross walls separating the cells in the phloem and have lots of minute pores. These cross-walls look like a sieve and so are called sieve plates. The holes in the sieve plates allows rapid flow of manufactured food substances through the sieve tubes.
How is sieve tube different from companion cells?
The sieve tube elements are specialized elongated cells in the phloem that connect end to end forming a tube. The main function of this tube is to transport nutrition in the form of carbohydrates. Sieve cells have no nucleus, ribosomes and cytoplasm, meanin they cannot carry out primary metabolic activities. The companion cells, which are closely associated with the sieve tube elements, carry out the their metabolic functions.
