The Role of Specialized Companion Cells in the Phloem
What is the role of a specialized companion cell in the phloem?
A) It transports sugars from the palisade mesophyll cell to the companion cell.
B) It transports sugars from the companion cell to the palisade mesophyll cell.
C) It transports water from the palisade mesophyll cell to the companion cell.
D) It transports water from the companion cell to the palisade mesophyll cell.
Answer:
A) It transports sugars from the palisade mesophyll cell to the companion cell.
The specialized companion cell in the phloem plays a crucial role in the translocation of sugars within plants. These companion cells are connected to the palisade mesophyll cells via plasmodesmata, forming a network that allows for the transfer of essential nutrients.
Specifically, the specialized companion cell facilitates the transportation of sugars, such as sucrose, from the palisade mesophyll cells to itself. From there, the sugars can be directed into the phloem sieve-tube elements (STEs) for distribution to other parts of the plant.
This process requires energy in the form of ATP and is vital for the proper growth and development of the plant. The movement of sugars through the phloem ensures that essential nutrients are distributed efficiently to support various cellular functions.