companion cell: meaning, definition, pronunciation and examples
Very LowTechnical/Scientific
Quick answer
What does “companion cell” mean?
A specialized plant cell found adjacent to a phloem sieve tube element, providing metabolic support and helping to maintain the sieve tube's function.
Audio
Pronunciation
Definition
Meaning and Definition
A specialized plant cell found adjacent to a phloem sieve tube element, providing metabolic support and helping to maintain the sieve tube's function.
A type of parenchyma cell in the phloem tissue of vascular plants that is closely associated with a sieve tube element; it assists with loading and unloading sugars and other organic molecules into the sieve tubes and helps regulate cellular activities.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences. Spelling of related terms may follow regional conventions (e.g., 'phloem' vs 'phloem').
Connotations
Purely technical, no connotative difference.
Frequency
Exclusively used in academic botany and biology texts in both regions; extremely rare in general discourse.
Grammar
How to Use “companion cell” in a Sentence
The companion cell is located [prepositional phrase: e.g., next to the sieve tube].Companion cells [verb: e.g., facilitate, support, load] the sieve tube elements.Vocabulary
Collocations
Examples
Examples of “companion cell” in a Sentence
verb
British English
- The specialised tissue is designed to companion the sieve elements.
American English
- The specialized tissue is designed to companion the sieve elements.
adjective
British English
- The companion-cell function is critical for phloem transport.
American English
- The companion-cell function is critical for phloem transport.
Usage
Meaning in Context
Business
Not used.
Academic
Used exclusively in botany, plant physiology, and biology textbooks and research papers.
Everyday
Not used.
Technical
Core term in plant anatomy and physiology.
Vocabulary
Synonyms of “companion cell”
Neutral
Weak
Vocabulary
Antonyms of “companion cell”
Watch out
Common Mistakes When Using “companion cell”
- Misspelling as 'companion sell'.
- Using it to refer to any cell that is simply next to another.
- Confusing it with 'guard cell' (which is in leaves).
FAQ
Frequently Asked Questions
No, companion cells are essential for the proper function of phloem, which transports nutrients. Without them, sieve tube elements would die, disrupting the plant's nutrient distribution system.
No, it is a term specific to plant anatomy and has no direct equivalent in animal cell biology.
No, they are two distinct but functionally linked cell types that work together in the phloem. The sieve tube element is the main conduit for sap flow, while the companion cell supports it.
They are located immediately adjacent to sieve tube elements within the phloem tissue of stems, leaves, and roots.
A specialized plant cell found adjacent to a phloem sieve tube element, providing metabolic support and helping to maintain the sieve tube's function.
Companion cell is usually technical/scientific in register.
Companion cell: in British English it is pronounced /kəmˈpænjən sɛl/, and in American English it is pronounced /kəmˈpænjən sɛl/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think of a 'companion' who helps you on a journey. The companion cell helps the sieve tube on its journey transporting food (sap) through the plant.
Conceptual Metaphor
SUPPORT IS COMPANIONSHIP (The cell acts as a supportive partner to the sieve tube).
Practice
Quiz
What is the primary role of a companion cell?