Question

Xylem is associated with the translocation of (a) Water (b) Mineral (c) Some organic nitrogen and hormone (d) All of these

Short answer

The correct answer is (d) All of these

Step-by-step solution

Identify the function of xylem

Xylem is a type of tissue in vascular plants that performs the function of transporting water from roots to stems and leaves, but it also transports nutrients.

Evaluate the options

Option (a) is 'Water'. This is accurate as one of the main functions of xylem is to transport water in plants. Option (b) is 'Mineral'. Xylem is responsible for the transport of nutrients in plants, so this answer is also correct. Option (c) is 'Some organic nitrogen and hormone'. Xylem vessels also aid in the transport of some organic materials and hormones in the plant system. So, this is also a correct answer. Option (d) is 'All of these'. Seeing as all the previous statements are accurate, this answer would be true because it includes all of the functions of xylem.

Confirm the answer

Since all the options (a, b, c) are correct responses for the function of xylem in a plant, the correct answer would be option (d), which suggests that all of them are accurate.

Key concepts

Water Transport

In plants, water transport is a vital function that ensures the survival and growth of the plant. Xylem is the primary tissue that takes on this crucial role. It is made up of specialized cells that form a network of vessels and tracheids. These tubes function like straws, drawing water upward from the roots to all parts of the plant.

Water is absorbed from the soil through the roots, moving into the xylem vessels. These vessels utilize capillary action and cohesion to transport water to the leaves, where it is used in photosynthesis. Transpiration, the process of water evaporation from leaves, creates a negative pressure that further helps draw water up through the xylem.

This journey from roots to leaves is essential, as it not only provides water for photosynthesis but also helps regulate plant temperature and maintains cell structure.

Mineral Transport

Along with water, minerals are transported through the xylem to various parts of the plant. These minerals are essential nutrients that plants need for biochemical processes and structural integrity.

Minerals dissolved in water include potassium, magnesium, calcium, and nitrates, among others. They are absorbed from the soil through root hairs and enter the xylem vessels. Once inside, these nutrients travel along with the water stream.

• Calcium helps in cell wall structure.
• Potassium regulates stomatal opening and closing.
• Magnesium is a crucial component of chlorophyll.

The transportation of these minerals through the xylem ensures that each part of the plant gets the necessary elements to thrive.

Organic Nitrogen Transport

Xylem doesn't only transport inorganic elements but also plays a role in moving organic nitrogen compounds. Organic nitrogen is vital for the synthesis of amino acids, proteins, and nucleic acids, critical components for plant growth and reproduction.

Some of the organic nitrogen compounds are synthesized in the roots or absorbed from the soil in the form of amino acids or small peptides. These reserves are then translocated through the xylem vessels to areas of growth, such as leaves and developing seeds.

This process is crucial for plant development, especially during periods of active growth when nitrogen demands are high.

Hormone Transport

The transport of hormones is another essential function of xylem. Plant hormones, or phytohormones, like auxins and cytokinins, play significant roles in regulating plant development and responses to environmental stimuli.

Although phloem is primarily responsible for distributing plant hormones, the xylem also plays a part in moving some of these molecules. The translocation of hormones through the xylem helps coordinate growth, such as cell division and elongation, phototropism, and the response to stress.

By facilitating hormone movement, the xylem ensures that different plant parts are in sync with each other's physiological needs, allowing for smooth growth and response to environmental changes.

Vascular Tissue in Plants

Vascular tissue is the plant's internal transport system, composed of xylem and phloem. Xylem and phloem perform complementary functions that are crucial for sustaining plant life.

Xylem is responsible for ascending the transport of water and minerals from roots to the leaves. In contrast, phloem distributes sugars and other metabolic products downward from the leaves to the rest of the plant.

• Xylem cells are typically dead at maturity and have thickened walls, allowing for rigidity and support.
• Phloem cells are alive and facilitate the transport of organic compounds.

Together, these two components ensure that plants maintain the flow of substances essential for their growth, reproduction, and survival.