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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.
Function of root hair cell?
To absorb water and nutrients from the soil.
What are the constituents of phloem?
The phloem consists mainly of sieve tubes, companion cells, phloem fibers, and parenchyma cells. Sieve tubes are responsible for transporting sugars and other organic compounds, while companion cells support sieve tube function. Phloem fibers provide structural support, and parenchyma cells store nutrients.
What are nucleated cells of the phloem which aid in the physiology of sieve tubes called?
The nucleated cells in the phloem that aid in the physiology of sieve tubes are called companion cells. These cells are closely associated with sieve tube cells and provide metabolic support, such as loading and unloading of nutrients, for the sieve tubes.
What is the shape of companion cells?
Companion cells are typically elongated and have a dense cytoplasm. They are closely associated with sieve elements in the phloem and play a crucial role in supporting the function of these sieve elements by providing them with nutrients and energy.
What are Structures in phloem involved in translocation of sugars?
In phloem, the primary structures involved in the translocation of sugars are sieve tubes and companion cells. Sieve tubes are elongated cells that form a continuous pathway for the flow of phloem sap, which primarily contains sugars like sucrose. Companion cells, which are closely associated with sieve tubes, support their function by providing metabolic support and facilitating the loading and unloading of sugars. Together, these structures enable efficient transport of nutrients throughout the plant.
Loaded in if sucrose is actively loaded into sieve tube?
Yes, sucrose is actively loaded into sieve tubes by companion cells that pump sucrose from the photosynthetic cells into the sieve tubes. This process requires energy and allows for long-distance transport of sucrose through the phloem.
Which of this following froms an important component of phloem tissue?
Sieve tubes and companion cells are important components of phloem tissue in plants. Sieve tubes are responsible for transporting sugars and other organic compounds, while companion cells support sieve tube function by providing energy and resources.
What is the structure of the Phloem?
Phloem is composed of sieve elements and companion cells. Each sieve element has a companion cell that provides ATP and other necessary support to the sieve element. In addition to this there are sieve plates that separate sieve cells.
Do mature cells of phloem tissue in angiosperms have nuclei?
Mature phloem cells in angiosperms, specifically the sieve tube elements, lose their nuclei as they differentiate. This adaptation allows for more efficient transport of sugars and nutrients. However, companion cells, which are associated with sieve tube elements, retain their nuclei and play a crucial role in maintaining the function of the sieve tubes. Thus, while mature sieve tube elements lack nuclei, the companion cells do have them.
What is the sugar-transporting cells in angiosperms?
In angiosperms, the sugar-transporting cells are known as sieve tube cells, which are part of the phloem tissue. These cells are responsible for transporting sugars, mainly sucrose, from photosynthetic tissues to non-photosynthetic parts of the plant for energy and growth. Sieve tube cells are connected end-to-end to form sieve tubes, allowing for efficient long-distance transport of sugars throughout the plant.
What is the difference between companion cell and sieve tubes?
Companion cells have the structure of a 'normal' plant cell. Sieve tubes don't have nuclei, tonoplasts and ribosomes. Also there are no sieve plates in a companion cell, whereas there are in sieve tubes.
What is the specialized cell that helps control the movement of sugars through sieve tubes called?
Companion cells are specialized cells that help control the movement of sugars through sieve tubes in plants. They provide metabolic support to sieve tube elements and help maintain the pressure gradient that drives the flow of sugars.
How is xylem vessels differ from sieve tubes?
Xylem vessels and sieve tubes serve different functions in plants. Xylem vessels are responsible for transporting water and dissolved minerals from the roots to other parts of the plant, while sieve tubes are involved in the transport of sugars and nutrients from the leaves to the rest of the plant. Additionally, xylem cells are typically dead at maturity and have thick, lignified walls, whereas sieve tube elements are living cells that have specialized structures called sieve plates to facilitate the flow of sap.
