Problem 79 - Objective Biology for NEET

Question

During symplastic pathway water moves through (a) Cytoplasm (b) Plasmodesmata (c) Cell membranc (d) All of thesc

Step-by-Step Solution

Answer

The correct options are (a) Cytoplasm and (b) Plasmodesmata.

Step 1: Understand Symplastic Pathway

The symplastic pathway is one of the two main methods of water transport in plants. In this pathway, water moves along the cytoplasm of the cells, transferring from one cell to the next through structures called plasmodesmata.

Step 2: Analyze the Options

With the understanding of symplastic pathway, we look at the options. (a) Cytoplasm is involved as it is the medium through which water moves, so it is correct. (b) Plasmodesmata are the structures through which water moves from one cell to another, so this is also correct. (c) The cell membrane is involved only in the initial movement of water from the soil into the root hair cells, not in the symplastic pathway across cells, so this is not correct. (d) Considering all the options, it says 'all of these' which is incorrect as we proved that cell membrane is not involved in the symplastic pathway.

Step 3: Select the Correct Answer

Based on the analysis, the options (a) Cytoplasm and (b) Plasmodesmata are the parts where the water moves through during the symplastic pathway. The other options do not completely reflect the movement of water in this pathway.

Key Concepts

Water Transport in Plants

Plants have developed ingenious methods to move water and nutrients from the roots to various parts. One essential method is the symplastic pathway, which is part of the broader concept of water transport in plants. In this process, water moves internally through the plant cells.

The symplastic pathway relies on the cytoplasmic network within the plant cells. Water travels through the cytoplasm, passing from one cell to the next via small channels called plasmodesmata. This allows for seamless movement without crossing cell membranes repeatedly.

Other methods include the apoplastic pathway, where water moves through the cell walls and spaces outside the plasma membrane. However, the symplastic pathway is crucial for the integration and communication between cells. Understanding these pathways helps us appreciate how plants efficiently distribute water and nutrients essential for their growth and survival.

Plasmodesmata

Plasmodesmata are small, tubular structures that connect the cytoplasm of adjacent plant cells. Acting like microscopic bridges, they allow for the direct transfer of water and nutrients between cells in the symplastic pathway.

These structures are vital for maintaining communication and coordination among plant cells. They ensure that water moves smoothly throughout the plant, bypassing the need for water to exit and enter each cell separately. This accelerates the transport process and helps maintain internal equilibrium.

Plasmodesmata are not static; they can expand or contract based on the plant's needs. This flexibility helps regulate the flow of substances, making them a key component in plant development and response to environmental changes. Through the use of plasmodesmata, plants can control and optimize the distribution of resources, ultimately aiding in their survival and growth.

Cytoplasm Movement

In the symplastic pathway of water transport, the movement occurs primarily through the cytoplasm of plant cells. The cytoplasm, a gel-like substance within the cell, facilitates the movement of water and dissolved nutrients.

This movement is driven by osmosis and pressure gradients within the plant. Once water enters the root cells, it quickly moves through the cytoplasm and can spread across vast cell networks via plasmodesmata. The cytoplasm thus acts as both a medium and a conveyor for essential substances, ensuring that each cell receives necessary nourishment.

The cytoplasmic movement is vital for plant health and growth, as it allows for distribution without losing control over the cell’s internal environment. By efficiently managing water and nutrients within cells, plants can maintain homeostasis, adjust to changing conditions, and ensure optimal functioning of all cellular processes.