Mineral Nutrition (SAQs)

Botany-2 | 2. Mineral Nutrition – SAQs:
Welcome to “SAQs” in “Chapter 2: Mineral Nutrition”. This page includes the most important FAQs from previous exams. Each answer is provided in simple English, followed by a Telugu explanation, and then presented in the exam format. This method ensures you’re well-prepared to achieve great results in your final exams.

---

SAQ-1 : Explain the steps involved in the formation of root nodule.

Introduction

Root nodules are special growths on the roots of leguminous plants like beans and peas. These nodules are essential because they help convert atmospheric nitrogen into a form that plants can use for growth. This process relies on a close partnership between the plant and Rhizobia bacteria and involves several organized steps.

Formation of Root Nodules

1. Attracting Rhizobia to the Plant Roots: The process begins when legume plant roots release chemicals, such as sugars and amino acids, into the soil. These chemicals act like signals, attracting Rhizobia bacteria, which are crucial for forming root nodules.
2. Colonization of Root Hair Cells by Rhizobia: The Rhizobia detect these signals, start multiplying, and attach themselves to the root hair cells. This attachment marks the beginning of their beneficial relationship with the plant.
3. Infection Thread Formation: Once attached, the root hairs curl around the bacteria, creating an infection thread that acts as a pathway for the Rhizobia to enter deeper into the root.
4. Initiating Nodule Formation: When the bacteria reach the root cortex, they stimulate the plant cells to divide, starting the formation of the root nodule.
5. Formation of Specialized Cells: Inside the developing nodule, the plant cells transform into specialized nitrogen-fixing cells that house the Rhizobia and support the nitrogen fixation process.
6. Establishment of a Connection for Nutrient Exchange: Finally, the new root nodule establishes a vascular connection with the plant. This connection facilitates the exchange of nutrients between the plant and the Rhizobia. Through this partnership, the bacteria receive the nutrients they need, and the plant benefits from the fixed nitrogen, especially in nitrogen-poor soils.

Summary

The formation of root nodules is a complex but fascinating process. It starts with the legume roots attracting Rhizobia bacteria, which then colonize the root hairs and move into the root through an infection thread. The bacteria stimulate the plant to form a nodule, which eventually becomes a site for nitrogen fixation. This mutual relationship allows legume plants to thrive and enrich the soil with essential nutrients. Understanding this process highlights how legumes contribute to soil fertility and their own growth.

---

SAQ-2 : Write in brief how plants synthesize amino acids.

Introduction

Amino acids are like the building blocks of proteins and are essential for plants to grow and stay healthy. Plants create these important compounds from simple substances they get from soil, air, and water. This happens through a series of complex reactions that transform these basic elements into something vital for the plant.

The Process of Amino Acid Synthesis

1. Nitrogen Absorption from Soil: The journey of amino acid synthesis starts with plants taking in nitrogen from the soil. This nitrogen usually comes in the form of nitrates and ammonium ions. For the plant to use this nitrogen to make amino acids, the nitrates must first be changed into ammonium. Imagine nitrates like the raw materials that need to be processed before they can be used in a factory.
2. Nitrogen Fixation: In legumes like beans or peas, the process is even more fascinating. These plants have a special relationship with nitrogen-fixing bacteria in their roots. These bacteria take atmospheric nitrogen, which plants can’t use directly, and convert it into ammonia. The plant then uses this ammonia to create amino acids. It’s like having a helpful partner that turns raw materials into something you can use.
3. Conversion to Organic Form: Once the plant has its nitrogen, it needs to convert it into a form it can use. This step, called nitrogen assimilation, involves various enzymes working together to transform the nitrogen into an organic form. Think of this as the step where the plant is preparing its ingredients before starting the actual cooking process.
4. Production of Amino Acids: With the nitrogen now in the right form, the plant combines it with a carbon skeleton from carbohydrates. This combination is essential for making amino acids. Enzymes like aminotransferases and dehydrogenases play a crucial role in this stage, guiding the process much like a chef following a recipe to make a dish.
5. Incorporation into Proteins: Finally, once the amino acids are made, they are used to build proteins. Inside the plant cells, ribosomes help put these amino acids together into proteins. These proteins are crucial for the plant’s growth, development, and overall health. It’s similar to how the final product in a factory is packaged and used to build something essential.

Summary

The synthesis of amino acids in plants is a fascinating journey that starts with nitrogen absorption from the soil or atmosphere. This nitrogen is converted into an organic form and combined with carbohydrates to make amino acids. These amino acids are then used to create proteins, which are vital for the plant’s survival. This process shows how plants can transform simple nutrients into complex and necessary components for their growth and health.