Question

The tubular channels formed by the connected plasma membrane of adjacent plant cells are called as

• A. Plasmodesmata
• B. Symplast
• C. Middle lamella
• D. Apoplast

Hint:

Think of plasmodesmata as "cytoplasmic bridges."
They are essential for viral movement within a plant.
Remember the distinction: Apoplast = Dead/Cell Wall path; Symplast = Living/Protoplast path.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks to identify the specific anatomical structures in plants that act as channels or bridges, physically connecting the cytoplasm and plasma membranes of neighboring cells.
Detailed Explanation:

• Definition of Plasmodesmata:
Plasmodesmata (singular: plasmodesma) are microscopic channels that traverse the cell walls of plant cells and some algal cells, enabling transport and communication between them.
These channels are lined by the plasma membrane, making the cytoplasm of adjacent cells continuous.

• Structure and Function:
Each plasmodesma contains a central tube of endoplasmic reticulum known as a desmotubule.
They play a crucial role in the movement of water, nutrients, and signaling molecules (like proteins and RNA) through the symplastic pathway.

• Analysis of other options:
Symplast: This refers to the entire system of interconnected protoplasts (cytoplasms) of a plant, linked by plasmodesmata. It is a pathway, not the channel itself.
Apoplast: This is the space outside the plasma membrane, consisting of cell walls and intercellular spaces. It facilitates the non-living transport pathway.
Middle lamella: This is a pectin-rich layer that acts as "glue" between the primary cell walls of adjacent cells. It does not provide cytoplasmic connectivity.

Step 2: Final Answer:
The tubular channels that connect the plasma membranes and cytoplasms of adjacent plant cells are plasmodesmata.