phloem
/'flouəm/
Học thuậtThân thiện
Definition
- Noun:
- (Botany) The vascular tissue in plants that transports synthesized food substances (such as sugars) from the leaves to other parts of the plant where they are needed or stored. It consists primarily of sieve tubes and companion cells.
Usage
- Noun:
- The phloem is responsible for distributing sugars produced during photosynthesis.
- Damage to the phloem can disrupt the flow of nutrients within a tree.
- In a tree trunk, the phloem is located just inside the bark.
Examples
- Noun:
- Sugars are transported from the leaves to the roots through the phloem.
- The scientist studied the structure of the phloem under a microscope.
- Aphids often feed by inserting their mouthparts directly into the plant's phloem.
Advanced Usage
- "Phloem loading": The active process of transporting sugars into the sieve tubes of the phloem.
- Phloem loading requires energy and specific transport proteins.
- "Phloem sap": The fluid, rich in sugars and other compounds, that flows through the phloem.
- The composition of phloem sap varies between plant species.
Variants and Related Words
- Bast: An older, sometimes synonymous term for phloem, especially the fibrous part.
- Sieve tube element: The main conducting cell type within the phloem.
- Companion cell: A specialized cell adjacent to sieve tube elements that supports their function.
Synonyms
- Bast (in specific contexts, though "phloem" is the modern scientific term).
Related Concepts (Not Phrasal Verbs/Idioms)
- Xylem: The other main vascular tissue in plants, which transports water and minerals from roots to leaves. The phloem and xylem are often mentioned together.
- The vascular bundle contains both xylem and phloem.
- Vascular tissue: The general term for the transport tissues in plants, including phloem and xylem.
- Translocation: The process of transporting organic nutrients via the phloem.
Noun
- (botany) tissue that conducts synthesized food substances (e.g., from leaves) to parts where needed; consists primarily of sieve tubes