If sieve tube member becomes blocked which process is impaired?
Transport of lipids
Transport of gases
Transport of water
Transport of sugar
Transport of minerals
Transport of sugar
If a sieve tube member becomes blocked, the process that is impaired is the transport of sugar. Sieve tube members are responsible for transporting sugars, primarily sucrose, throughout the plant. These cells form the phloem tissue, which functions to transport sugars from source regions (such as leaves) to sink regions (such as roots, stems, and developing fruits). The blockage of sieve tube members would disrupt the flow of sugar and hinder the plant's ability to distribute energy-rich molecules to different parts of the plant.
If a sieve tube member becomes blocked, the process that is impaired is the transport of sugar. A sieve tube member is a specialized cell found in phloem tissue, which is responsible for transporting sugars, mostly in the form of sucrose, from the leaves to other parts of the plant. When a sieve tube member becomes blocked, the flow of sugar is disrupted, potentially leading to reduced energy production and hindered growth in the plant.
To understand why the transport of sugar is impaired when a sieve tube member becomes blocked, it is important to know how the transport system in plants works. Plants have two main vascular tissues responsible for transporting fluids throughout the plant: xylem and phloem. Xylem primarily transports water and minerals from the roots to the rest of the plant, while phloem transports sugars, amino acids, and other organic compounds.
Phloem tissue consists of two types of cells: sieve tube members and companion cells. Sieve tube members are long, tube-like cells that form a continuous network throughout the plant. Companion cells are specialized cells located adjacent to each sieve tube member and provide metabolic support to the sieve tube members.
The transport of sugar in the phloem occurs through a process called translocation. Sugars produced in the leaves during photosynthesis are actively loaded into sieve tube members by companion cells at the source (usually the leaves). This loading process creates a high concentration of sugars in the sieve tube members, generating a pressure gradient that drives the movement of sugars to areas of lower concentration.
However, if a sieve tube member becomes blocked, either due to physical damage or the presence of obstacles like air bubbles or substances that clog the sieve plates, the flow of sugar is disrupted. This blockage prevents the movement of sugars to other parts of the plant, impairing the transport of sugar.
It is worth mentioning that the transport of lipids, gases, water, and minerals in plants rely on other specialized tissues and mechanisms. Lipids, for example, are transported through the plant as part of membrane components or storage vacuoles. Gases are exchanged through specialized pores called stomata on the surface of leaves. Water is primarily transported through the xylem tissue via capillary action and transpiration. Minerals are also transported through the xylem tissue, mostly by the process of active transport.
In summary, when a sieve tube member becomes blocked, it impairs the transport of sugar in plants, which can have detrimental effects on the plant's growth and overall functioning.