NCERT Solutions Class 11 Biology Chapter 12

NCERT Solutions for Class 11 Biology Chapter 12

NCERT Class 11 Biology Chapter 12 – Mineral Nutrition educates students about inorganic plant nutrition and elements essential for the growth of a plant. Students will also learn about the role these essential elements play in plant growth, the mechanism by which they are absorbed, and the symptoms of serious deficiency in this chapter. 

NCERT Solutions offered by Extramarks provide accurate answers to the questions given at the end of every chapter of the NCERT textbook. Extramarks offers NCERT Solutions for Class 11 Biology Chapter 12 to help students answer the questions and perform better in exams. The solutions also aid in understanding the concepts in a better way.

NCERT Solutions for Class 11 Biology Chapter 12 – Mineral Nutrition 

The subject-matter experts at Extramarks prepare NCERT Solutions keeping the latest CBSE guidelines in mind. You can easily access NCERT Solutions for Class 11 Biology Chapter 12 on Extramarks in offline and online modes.

NCERT Biology Class 11 Mineral Nutrition 

NCERT Solutions for Class 11 Biology Chapter 12 provided by Extramarks are curated in a way that makes referring to all answers to textbook questions easy. The answers have detailed explanations and are broken down into smaller parts for better understanding.

Solutions have been prepared by subject-matter experts following the latest CBSE syllabus and guidelines so that students can give accurate answers and perform better in examinations.

NCERT Solution Class 11 Biology Chapter 12 Mineral Nutrition 

All living creatures have certain fundamental needs such as the consumption of macromolecules (like starches, fats, and proteins), water, and minerals to promote development and advancement. The chapter discusses inorganic plant sustenance, and students will learn the technique for recognising components that play a basic part in plant development and advancement. Students will also read about the functions of the fundamental components, their lack of indications, and the retention of the basic components.

In 1860, the German botanist Julius Von Sachs demonstrated that plants could be developed without the presence of soil. It was done with the help of a defined nutrient solution. This process that does not require soil but the nutrient solution is known as tank-farming. Tank farming is used for vegetable farming for business purposes. It should be noted that circulation for nutrition solutions with sufficient air is a must for a plant’s ideal development. 

From then on, multiple techniques were utilised to decide the mineral solution ideal for plants. The different techniques all include growing plants in a mineral solution without soil. Filtered water and mineral solutions like salts are required in these techniques. 

A series of tests were conducted where plants were grown in nutrient solutions and a component was either added, removed, or given in shifted fixation. After these tests, the most appropriate mineral solution for plant development was obtained. It was possible to distinguish basic components and find out their inadequacy indicators. 

Distribution of Marks for Mineral Nutrition 

The Mineral Nutrition chapter is covered under Unit IV, which carries a topic weightage of 18 marks. 1 mark or 5 marks questions may be asked in exams from it.

Advantages of Class 11 Biology Mineral Nutrition NCERT Solution 

NCERT Solutions for Class 11 Biology Chapter 12 contain comprehensive answers that students can refer to while attempting to practice questions given at the end of the Chapter 12 NCERT textbook. 

Extramarks NCERT Solutions are reliable enough to be considered the best guide option for examination preparation. All questions which are a part of Chapter 12 Mineral Nutrition are covered well in Class 11 Chapter 12 Biology NCERT Solutions.

Related Questions 

Q1. A cut apple that has been kept for a while in the air turns brown. This occurs due to the presence of :

  • Ferrous ions
  • An enzyme action
  • Ferric ions
  • Magnesium ion

 

Answer: An enzyme action

Explanation: When an apple is cut, the enzyme polyphenol oxidase (PPO) present in the apple comes in contact with the oxygen molecules in the air. Oxygen molecules oxidise polyphenol into o-quinones which react with amino acids to produce melanins. The production of melanins gives the apple its brownish appearance.

Q2. The oxygen evolved during photosynthesis comes from water molecules. Which one of the following pairs of elements is involved in this reaction?

  • Magnesium and chlorine
  • Manganese and potassium
  • Manganese and chlorine
  • Magnesium and molybdenum

 

Answer: Manganese and Chlorine

Explanation: The photolysis of water is aided by chlorine, manganese, and calcium during the light reaction of photosynthesis.

Q3. Mention the functions of Leghaemoglobin.

Leghaemoglobin is a hemoprotein found in nitrogen-fixing root nodules of leguminous plants and has the following functions:

  • It protects nitrogenase (an enzyme) from being deactivated by oxygen as nitrogenase is sensitive to oxygen. 
  • It provides enough oxygen to bacteria for respiration. 

Q4. Explain the steps involved in the formation of root nodules.

The formation of root nodules involves multiple steps and sequencing of a series of interactions between the roots of the host plant and Rhizobium. Here are the steps involved:

Step 1: Rhizobia multiplies and colonizes the surroundings of the roots and epidermal. The root hair cells get attached to it. When the root hair curls, the invasion of bacteria begins.

Step 2: Upon the production of an infection thread, the bacteria are carried into the cortex of the root, and nodule formation is initiated.

Step 3: The bacteria is released from the thread into the cells which lead to the differentiation of specialized cells for nitrogen fixation.

Step 4: This leads to the formation of a direct vascular connection with the host with the help of nodules. It helps in the exchange of nutrients.

 

FAQs (Frequently Asked Questions)

Mineral salt is absorbed by plants easily through the roots with the help of root hair and zones of extension. Minerals that plants have collected from the soil are assimilated as ions. Absorption of minerals takes place in two phases: Initial and Metabolic. 

The initial stage involves ions being taken up rapidly into the apoplast (free spaces of the cells). Apoplast includes cell dividers and intercellular spaces. The particles that are absorbed by the free space are not interchangeable (eg: unlabelled K+ particles cannot be replaced with labelled K+ particles). The absorption of minerals from soil by root hair occurs with a simple diffusion process and does not require energy. The diffusion process involves the movement of solute and minerals from a place they are highly concentrated (soil) to a place of lower concentration (root hair). The initial stage can be considered as passive transport of minerals. 

The metabolic stage involves ions passing into internal space. The transport of minerals here takes up energy and hence this stage can be considered an active transport of minerals. Flux is the movement of ions. Influx on the other hand is the movement of ions into the cell while efflux is the outwards movement. 

 

In plants, Chlorosis, Necrosis, Delay in flowering, Deformation, and Inhibition of cell division are the five deficiency symptoms. Here is how they occur:

Chlorosis: This is caused because of N, K, Mg, S, Fe, Mn, Zn, and Mo deficiency.

Inhibition of cell division: N, Mo, K, and S deficiency are the reasons for this. 

Delay in flowering: This occurs because of reduced levels of Mo, S, and N.

Necrosis: This is caused because of Mg, Ca, Cu, and K deficiency.

Deformation: This is caused by Boron deficiency.

 

As explained in Class 11 Biology Chapter 12 Mineral Nutrition, observing the morphological changes in every part of the plant is what should be followed to determine the real deficient mineral. The standard tables and the changes should then be compared. One has to check experimentally (which is done by adding the nutrients one after the other) by noting the recovery of the plant in response to adding a particular nutrient. The deficient mineral element can be found with the help of this method.

The nitrogen cycle includes converting Nitrogen into biologically accessible forms. This can be done in three ways:

  • Lightning And UV radiation: Lightning And UV radiation convert Nitrogen gas to Nitrate. 
  • Industrial processes: Through industrial processes, nitrogen can be reduced to Ammonia and Urea.  
  • Nitrogen-fixing bacteria: Nitrogen-fixing bacteria aid in converting nitrogen to ammonia.

When lightning occurs, pressure and high temperature in the air convert nitrogen to its oxides. These oxides keep revolving in the air until rainwater dissolves them into nitric and nitrous acids. Multiple life forms then use these acids. Rain causes the nitric and nitrous acids to merge with the soil and form soil organic nitrogen. This process of nitrogen being converted into a biologically accessible form is called atmospheric nitrogen fixation. 

Particular deficiency characteristics can be seen in every element. An element’s deficiency cannot be fulfilled by supplying some other element. Noting down all the symptoms in different parts of the plants is the first step while the next one is comparing the collected information and the standard symptoms in a table to determine the mineral deficiency. 

NCERT Solutions Class 11 Biology Chapter 12 by Extramarks have been curated to help students prepare all the answers that are a part of the exercise questions of NCERT Class 11 Chapter 12 Biology. Diagrams are used to make them more understandable. Clear explanations of the answers help in learning and understanding them more easily and quickly.