Problem 37 - Objective Biology for NEET

Question

The functions of xylem are (a) Conduct water from root to stem and leaves (b) Conduct mineral from root to stem and leaves (c) Provide mechanical strength to plant (d) All of these

Step-by-Step Solution

Answer

(d) All of These

Step 1: Identification

Identify the distinct roles of the xylem listed in options (a), (b), and (c). Firstly, the xylem does indeed conduct water from the roots to the stem and leaves (option a). Secondly, the xylem is responsible for conducting minerals from the root to the stem and leaves (option b). Lastly, the xylem does provide mechanical strength to the plant (option c).

Step 2: Compilation

Compile the information. Since all three individual options (a, b, c) are accurate descriptions of the functions of xylem, therefore the most comprehensive answer is that the xylem performs all mentioned tasks.

Key Concepts

Water Conduction

Xylem is a vital tissue in plants, playing a crucial role in transporting water throughout the plant. This process is known as water conduction, where water moves from the root system up to the stem and leaves. It happens because of the cohesion and adhesion properties of water molecules.
Xylem vessels are like tiny pipes running through the plant. These vessels pull water upwards, thanks to the process called transpiration. Water evaporation from the leaves creates a suction force, which helps draw more water from the roots.
Without effective water conduction, plants would struggle to maintain their vital functions as water is essential for photosynthesis, nutrient transport, and cell structure.

• Water conduction relies on the transpiration stream
• Xylem vessels provide pathways for water movement
• Cohesion and adhesion help hold water molecules together

Mineral Conduction

Beyond transporting water, xylem is also integral in moving essential minerals from the soil to various plant parts. Plants absorb minerals through their roots in the form of ions dissolved in water.
Mineral conduction is essential for the plant's health as minerals serve as nutrients necessary for growth and development. For instance, nitrogen is vital for protein synthesis, while potassium assists in enzyme activation.
These minerals travel with water in the xylem vessels and reach different areas like leaves and stems, where they are involved in several biological processes.

• Minerals move as dissolved ions
• Transported alongside water through xylem vessels
• Crucial for plant nourishment and metabolic functions

Mechanical Strength in Plants

Besides transporting water and minerals, xylem provides mechanical strength to plants. This strength is vital for maintaining structure and allowing plants to stand upright against winds, rains, and their weight.
The xylem consists of thick-walled, lignin-rich cells, which contribute to the plant's rigidity. Lignin is a complex organic polymer that hardens cell walls, making them resistant to damage.
This mechanical support ensures plants can continue photosynthesis and grow in various environmental conditions. It also protects delicate tissues and provides a scaffold for other plant tissues.

• Xylem cells contain lignin for added strength
• Ensures structural integrity and stability
• Protection against environmental stressors