Important Questions Class 11 Biology Chapter 12

Important Questions Class 11 Biology Chapter 12 – Mineral Nutrition

Biology helps us understand our living world and how species function, evolve, and interact with each other and their surroundings. Biology permeates all aspects of our everyday life. Science is a broad subject that requires a basic understanding of core concepts to comprehend advanced-level topics taught in higher classes. Students must familiarise themselves with theories and essential concepts taught in the lower grade to understand advanced concepts better in higher classes. 

Chapter 12 of Class 11 is on Mineral Nutrition. Mineral nutrition is an important chapter in Class 11 Biology for exams like NEET, MH-CET, and board examinations. This chapter deals with different elements involved in plant nutrition and its significance.

Extramarks is one of the most trusted online learning platforms for lakhs of students across India. We offer authentic and reliable study material for students from Class 1 to Class 12. Students get access to NCERT solutions for each chapter that will help cover all theories and concepts on the Extramarks website. 

Having a robust study plan is vital to scoring good marks in Biology. First, students should thoroughly review all chapters from the NCERT textbook. Students should practice a good set of questions and go through solved papers to score excellent grades in exams. At Extramarks, we realize the importance of question-solving and have compiled questions from different sources, including the NCERT textbook, NCERT exemplar, other reference books, past years’ exam papers, etc. Our Biology subject matter experts have put together step-by-step solutions to help the students understand the concepts more clearly. Students may register on the Extramarks website to get access to the complete set of solutions for Important Questions Class 11 Biology Chapter 12 prepared by our faculty.

Extramarks’ website also offers plenty of study material that helps students in achieving their academic goals. Study materials include NCERT Solutions, CBSE revision notes, past years’ question papers, NCERT books, solutions to important questions, and more.

Access Mineral Nutrition Class 11 Important Questions & Answers for the Academic Year 2022-23.

Class 11 Biology Chapter-wise important questions are available for free to students, and these questions are perfect for self-study.

Check out CBSE Class 11 Biology Important Questions for other chapters as well:

CBSE Class 11 Biology Important Questions

Sr No. Chapters Chapters Name
1 Chapter 1 The Living World
2 Chapter 2 Biological Classification
3 Chapter 3 Plant Kingdom
4 Chapter 4 Animal Kingdom
5 Chapter 5 Morphology of Flowering Plants
6 Chapter 6 Anatomy of Flowering Plants
7 Chapter 7 Structural Organisation in Animals
8 Chapter 8 Cell the Unit of Life
9 Chapter 9 Biomolecules
10 Chapter 10 Cell Cycle and Cell Division
11 Chapter 11 Transport in Plants
12 Chapter 12 Mineral Nutrition
13 Chapter 13 Photosynthesis in Higher Plants
14 Chapter 14 Respiration in Plants
15 Chapter 15 Plant Growth and Development
16 Chapter 16 Digestion and Absorption
17 Chapter 17 Breathing and Exchange of Gases
18 Chapter 18 Body Fluids and Circulation
19 Chapter 19 Excretory Products and their Elimination
20 Chapter 20 Locomotion and Movement
21 Chapter 21 Neural Control and Coordination
22 Chapter 22 Chemical Coordination and Integration

Important Questions Class 11 Biology Chapter 12 With Solutions

A complete list of Important Questions Class 11 Biology Chapter 12 has been provided after compiling questionnaires from various sources. These questions contain the majority of the topics such as inorganic plant nutrition, methods to identify elements essential to growth, the role of the essential elements, mechanism of absorption, their major deficiency symptoms, significance, and the mechanism of biological nitrogen fixation. etc. These questions, along with their solutions, will help students better understand the chapter and revise crucial concepts without taking too much of their time and will be able to pay attention to other subjects as well.

This set of Important Questions Class 11 Biology Chapter 12 will give students a summary of the chapter and assist in refining general concepts. After going through these sets of important questions and solutions, students can prepare thoroughly and ensure excellent scores in board examinations as well as other competitive examinations.

Given below are a few Important Questions Class 11 Biology Chapter 12 and their solutions:

Question 1. Why is the purification of water and nutrient salts so important in studies involving mineral nutrition using hydroponics?

Answer 1: 

The method of growing plants in standardised nutrient solution in the absence of soil is called hydroponics. Soluble minerals in the form of impurities are present in water. It becomes essential to remove these impurities to purify water. Suppose this impure water is used in  the process of hydroponics. In that case, the impurity in the water can interfere with the experimental setup, and we will not be able to obtain the desired results. Hence the process of purification is necessary to allow the optimum growth of plants. Hence, hydroponics is important in mineral nutrition studies to purify various water and nutrient salts.

Question 2. Name the most crucial enzyme found in root nodules for N2 fixation. Does it require a special pink-coloured pigment for its functioning? Elaborate.

Answer 2: 

The most important enzyme found in root nodules for N2 fixation is Nitrogenase. Free nitrogen available in the air is converted to various nitrogenous compounds like ammonia with the help of the enzyme nitrogenase. It requires a special pink-coloured pigment for its functioning called leghaemoglobin. This is a Mo-Fe protein that facilitates catalysis. Leghaemoglobin is seen in root nodules of legumes. It combines with molecules of oxygen, thus helping in its removal. It is also called an oxygen scavenger. Creating such anaerobic conditions ensures the smooth functioning of the enzyme nitrogenase.

Question 3. What are the steps involved in the formation of root nodules?

Answer 3:

Root Nodules belong to the family Fabaceae or Leguminosae. Beans, peas, peanuts, etc., belong to this family. Root nodules from a symbiotic relationship between the leguminous plant species and host-specific bacteria. This bacteria is called the rhizobium.

The multiple steps for the formation of root nodules are:

  1. The rhizobium bacteria divide and attach themselves to epidermal cells and root hairs.
  2. The root hairs curl and are further invaded by bacteria.
  3. After the invasion of the bacteria, an infection thread is formed. This thread carries the bacteria to the cortex of the root and modifies them into bacteroids.
  4. Due to this, cortex and pericycle cells undergo cell division forming root nodules.
  5. The root nodules form a vascular connection. This leads to nitrogen fixation and initiation of nutrient exchange.

Question 4. How is sulphur important for plants? Name the amino acids in which it is present. 

Answer 4: 

Sulphur is an essential macronutrient that gets absorbed as an SO2-4 ion. It is an essential element without which the functioning of the plant cycle will be hampered. They constitute several coenzymes, vitamins (thiamine and biotin), proteins, and amino acids. Ferredoxin is an essential constituent of sulphur that is responsible for electron transfer in the process of photosynthesis. Sulphur plays a significant role in forming primary and quaternary structures of various proteins. They help in the bond formation of disulfide bridges. Sulphur is present in two amino acids, namely cysteine and methionine.

Question 5. What is the significance of Pseudomonas and Thiobacillus in the nitrogen cycle?

Answer 5:

The process in which anaerobic bacteria facilitate the conversion of solid nitrates into nitrogen gas back again is called denitrification. It is an important step in nutrient recycling. This process helps in contributing to the atmospheric nitrogen present. The various denitrifying bacteria include Micrococcus denitrificans, Thiobacillus denitrificans, Pseudomonas aeruginosa, etc. Of these, Pseudomonas and Thiobacillus are one of the major bacterias that help in the denitrification cycle.

Question 6. What does plant ash indicate?

Answer 6: 

Plant ash is the leftover residue that remains behind when plants are subjected to high temperatures. Water and protoplasm are the two key components of fresh plant weight. Dry weight comprises protoplasm mass alone while the water in the plant is escaped in the form of vapour. On heating further, the organic material in the plants converts to gases like carbon and nitrogen oxides. The minerals absorbed in this process cannot be converted into oxides readily; hence they remain as ash. Plant ash is an indication of absorbed plant minerals.

Question 7. How is the aspect of mobility of elements important to horticulture and agriculture?

Answer 7: 

The mobility of plants is an essential aspect of horticulture as well as agriculture. By observing various deficiency symptoms in plants, the farmer can clearly analyse the mobility of elements through his knowledge. It is helpful for an agricultural scientist, particularly a farmer, to understand the nature and cause of the disease with the aspect of mobility of elements. It helps to devise further plans for treating the affected plant based on observation.

Question 8. Why is it that deficiency symptoms appear first in certain plants in younger parts of the plant, while in others, they do so in mature organs?

Answer 8: 

The mobility of elements plays a crucial role in determining symptoms of deficiency appearing in both young and old plants. The older tissues exhibit deficiency symptoms when actively mobilised elements and get exported to younger parts of a plant. For example, the senescent leaves depict some deficiency symptoms through elements like nitrogen, potassium, and magnesium. This is due to the absence of these elements or a drop-down in their levels. In older leaves, such elements are available for mobilisation to younger leaves due to the breakdown of different biomolecules that contain these elements. While on the other side, elements like Ca and S are immobile and hence do not get transported from older plants. Hence they develop earlier in younger plants.

Key Topics Covered in Class 11 Biology Chapter 12 important questions

The questions included in our important questions booklet covers all the key concepts and topics covered in Class 11 Biology Chapter 12.

Questions  based on  topics  covered in the NCERT textbook are given below:

  • Methods to study mineral requirements of plants

This topic states the hydroponics technique in which plants are grown in nutrient-rich solutions. Apart from this, other methods mentioned discuss the culture of plants and their beneficiaries.

  • Toxicity of micronutrients 

This topic acknowledges the concentration of mineral ions in different tissues. It t describes how the dry weight of a particular plant species can be reduced to nearly 10%. These symptoms of toxicity are hard to identify and prove to be harmful and fatal. A brief understanding of the toxicity of micronutrients can help reduce its harmful effects for better functioning and maintenance of essential nutrients.

  • Role of various important nutrients in plant growth

Mineral nutrition is the naturally occurring inorganic nutrients present deep in the soil. These nutrients are responsible for various roles and functions of the plant and actively participate in the metabolic activities of plant cells. These include maintaining osmotic pressure, enzyme activity, permeability, etc. The chapter elaborates on the different nutrients and their fundamental roles. Nutrients are categorised as macronutrients and micronutrients.  

  • Micronutrients

Nutrients required in small amounts are termed micronutrients. They include;

copper, zinc, manganese, chlorine, boron, etc. All these elements, even though required in small quantities, are essential. Disbalance or absence in their quantities can cause severe effects on the nutrition cycle. 

  • Macronutrients

Nutrients required in more significant amounts as compared to micronutrients are called macronutrients. They are essential for regulating plant activities and various important plant cycles. These include nitrogen, sulphur, calcium, magnesium, sulphur, etc. They play an essential role in the nutrient cycle. 

  • Essential mineral elements

This topic in Biology Class 11 Chapter 12 important questions emphasises the various minerals and elements of plants, including magnesium, potassium, calcium, cobalt, hydrogen, oxygen, sulphur, phosphorus, nitrogen, nickel, iron, manganese, molybdenum, etc. 

  • Deficiency symptoms of essential elements

In biology mineral nutrition Class 11 Chapter 12, this section explains the variety of deficiency symptoms during the absence of essential elements. The various diseases include necrosis, chlorosis, premature fall of leaves, stunted plant growth, and much more. They are mainly caused due to certain host-specific bacteria or outspread of diseases. 

  • Mechanism of element absorption

It explains the mechanism process of element absorption and various other accompanying cycles. This mechanism can be carried out through 2 processes, mainly active and passive. Processes like the translocation of mineral salts through transpirational pull can be explained through this phenomenon. 

  • Metabolism of nitrogen

Soil acts as a reservoir for most essential elements and nutrients and facilitates quick transport to the plant. This chapter introduces us to the nitrogen cycle and the importance of the element nitrogen in plant activities.

  • Nitrogen fixation cycle

It describes the process through which plants obtain nitrogen. The nitrogen fixation cycle is facilitated with the help of various root nodules, bacteria, and some fungi that fix atmospheric nitrogen and provide them to the plants for carrying out essential functions in the plant cycle.

Benefits of Solving Important Questions Class 11 Biology Chapter 12

Biology, Physics, and Chemistry depend more on conceptual learning and a clear understanding of core topics. In Classes 8, 9, and 10, it’s important for students to form a good base in Science and other subjects to comprehend the complex concepts that would be introduced in higher classes. We recommend students to have a good study plan and include the best study materials that can help them during this journey. 

Extramarks provides the most reliable and comprehensive study materials for students from Class 1 to Class 12. Students can use our chapter-specific NCERT solutions and chapter notes to study core concepts covered in the NCERT textbook. Regularly solving questions has proven beneficial for students to revise the chapter and understand their weaknesses. Students can register on Extramarks website and get access to our Important Questions Class 11 Biology Chapter 12. This comes with step-by-step answers that will help students revise key topics from the chapter. It will definitely improve the confidence level among the students and also improve their speed and accuracy to get 100 % scores during school and board exams.

Given below are the benefits of regularly solving the NCERT textbook, NCERT exemplar, and past years’  question paper for Class 11 and Class 12 Biology:

  • Our  Biology faculty experts have carefully compiled the important questions from every chapter after thoroughly analysing the previous year’s questions. 
  • By solving Class 11 Biology Chapter 12 Important Questions and sets of other questions, students can improve their speed and inculcate a sense of time management early on that will help them in future competitive exams.
  •  Important Questions Class 11 Biology Chapter 12 are based on the NCERT books which are aligned with the latest CBSE guidelines. Our solutions are prepared by subject matter experts with decades of teaching experience. So students can comfortably rely on our study materials and be rest assured about their excellent performance during exams. 
  • All the questions covered in our set of Important Questions in Class 11 Biology Chapter 12 are based on various topics in the chapter – Mineral Nutrition. While solving these questions, students can revise the entire chapter and also clarify their doubts to ensure complete understanding.
  • Practising questions similar to exam questions paper patterns can boost students’ confidence to give  100% performance in their examinations and create their first milestone.

Q.1 Mineral enters a plant mainly by?



Active transport is the mediated process of moving particles across a biological membrane against a concentration gradient.

Q.2 Essential micronutrients are also known as?



A trace element is a chemical element that is needed in minute quantities for the proper growth, development, and physiology of the organism. A trace element is also referred to as a micronutrient.

Q.3 An essential element



Essential element are chemical nutrient that is vital for the successful growth and development of plant.

Q.4 Major nitrogen fixation is carried out by



Symbiotic bacteria carries out major nitrogen fixation. These bacteria live in symbiosis with another organism or each other.

Q.5 Hydroponics is a technique of growing plants in



Nutrient solution.

Hydroponics is a method of growing plants using mineral nutrient solutions, without soil.

Please register to view this section

FAQs (Frequently Asked Questions)

1. What are the important chapters in Biology in Class 11?

There are 22 chapters in the Class 11 Biology NCERT textbook syllabus. Some of the crucial chapters include the living world, cell cycle and division, the structural organisation in animals, and the breathing and exchange of gases. The units of plant physiology and human physiology are important, and a lot of questions are expected from these units. Students can refer to the step-by-step answer solutions given in our Important Questions Class 11 Biology Chapter 12 to get a better idea about the nature of questions and topics that are frequently asked in exams. All these study materials are available on our Extramarks website.

2. Why must students be aware of the weightage for NEET and other examination preparation?

It is recommended that students must know the entire syllabus for the board as well as the various competitive examinations they plan to appear in in the near future. It is better to have a basic understanding of chapters carrying more weightage and give importance to those chapters while preparing for their exams. In this way, the student will be able to prioritise different topics and units based on their weightage and get an insight into what they should focus on and the topics which require the least attention that can be dealt with at the last moment. Students can refer to the Chapter 12 Class 11 Biology important questions on the Extramarks website and explore a repository of study material exclusively prepared for students to excel and earn their much-coveted success.