Xam Idea Class 12 Biology Chapter 16 Solutions: Environmental Issues

Xam Idea Class 12 Biology Solutions Chapter 16 ‘Environmental Issues’ are prepared by our subject matter experts to help you prepare for Class 12 board exams easily. These solutions include topics like the different kinds of pollutants that are polluting our environment and the measures being taken by the government to control them. You will get to know about air pollutants, water pollutants, agrochemicals and their polluting effects. This chapter also touches upon solid and radioactive waste management. You learn about what is the greenhouse effect and how it impacts our climate along with measures to mitigate them. The details of ozone layer depletion and deforestation along with a case study of success in controlling these, are part of this chapter.

Xam Idea Solutions Class 12 Environmental Issues solutions have a total of 140 questions divided into 8 exercises. You will have full exposure to all kinds of questions that come in CBSE exams or other medical or engineering competitive exams such as NEET. So it is important to solve these questions with proper guidance for the right solution. There are MCQs to answer and short and long type questions also. Some questions are marked as HOTS which means “High order thinking” that would enhance your analytical abilities. Our solutions will help you assess yourself on how prepared you are for this chapter.

Our subject matter experts do thorough research before providing the Xam Idea solutions so you can be sure that our solutions are accurate and reliable. The solutions are simple to understand and explain all aspects of the chapter in detail. You have come to the right place if you are aiming to score high in board exams or crack other competitive exams.

Important Topics for Xam Idea Class 12 Biology Solutions Chapter 16: Environmental Issues

Environmental pollution is an unwanted effect in our environment which adversely affects the ecosystem. This is caused mainly due to an increase in population which has increased demands for water, automobiles, electricity, food, and shelter. This exerts enormous pressure on natural resources which leads to environmental degradation in the form of pollution and biodiversity.

Pollution – The undesirable change in the air, water, and soil which are physical, chemical, or biological in nature is called pollution. Pollutants are the agents that lead to such changes. Environment (Protection) Act, 1986 is an undertaking by the government of India which aims at controlling the pollution and protecting our environment.

Air Pollution – Air is important for respiration in living organisms and polluted air results in reduced crop production and their premature death. This harmful effect depends on what organisms are present in the air, how long the exposure to such pollutants has been, and how concentrated are the pollutants in the air.

Causes – Volcanic eruptions, garbage decomposition which results in the release of harmful gases, automobiles’ fossil fuel and gaseous release from industries, etc.

Type of air pollutants – There are mainly 2:

  • Particulate pollutants like dust particles, soot, metallic particles, etc.
  • Gaseous pollutants like carbon monoxide CO or nitrogen dioxide NO2, etc.

Harmful effects – They range from giddiness, decreased vision, low yield of plants, respiratory problems, etc.

Control methods – Various ways to control them are ESP (electrostatic precipitator) for removing particulate pollutants in thermal plants, scrubber for removing gases like SO2 from industrial plants.

Noise pollution – High levels of undesired sound gives rise to noise pollution.

Causes – Loudspeakers, social functions, industrial noises, Jet planes, etc.

Harmful effects – Increased heart rate, sleeplessness, stress, gastric problem, etc.

Control methods – Using sound-absorbent materials for industrial noises, horn-free zones around hospitals and schools, setting the timing for playing loudspeakers.

Water Pollution – Water is essential for the survival of all living beings but many kinds of waste disposal have started happening in the water. To protect water resources, the Water (Prevention and Control of Pollution) Act, 1974 was passed by the government of India.

Causes – Domestic sewage coming from residential as well as industrial areas like sand, faecal matter, etc. Industrial wastes like petroleum, heavy metals.

Harmful effects

  • Biomagnification – Increased concentration of toxicants at certain trophic levels of the food chain is called biomagnifications. This results in a decline in the bird population.
  • Eutrophication – Biological enrichment like nitrogen and phosphorus results in natural and accelerated ageing of the lake. This, in turn, converts the lake into the land.
  • Biochemical Oxygen Demand (BOD) – It is the amount of oxygen required for the microbial breakdown of biodegradable organic matter and is much higher in polluted water. This results in a sharp decline of oxygen downstream from sewage discharge affecting the mortality of fish and aquatic animals adversely.

Control methods – Using integrated wastewater treatment in cleaning water in 2 steps before discharging eliminates some of the pollutants. First, the conventional process of sedimentation, filtering, and chlorine treatment is applied. After that, a series of marshes were developed in which appropriate algae, fungi, plants, etc were grown which would neutralize, absorb, and purify water naturally.

Greenhouse Effect and Global Warming – Presence of gases like carbon monoxide, nitrogen dioxide in the atmosphere leads to warming of the earth. These are called greenhouse gases which prevent the escape of heat radiations of specific wavelengths that come back to the earth and in turn heats it. 

The gradual increase in the concentration of these greenhouse gases has led to a gradual increase in the earth’s temperature which is termed as global warming.

Causes – Increase in greenhouse gases which lets solar energy enter earth but prevent its escape.

Harmful effects – In the last 3 decades temperature of earth increased by 0.6%. It gives rise to the El Nino effect which is the odd changes in the weather.

Control methods – Reduction of deforestation, controlling the growth of the human population, planting trees are some of the methods to prevent global warming. 

Discussion of Exercises of Xam Idea Class 12 Biology Solutions Chapter 16: Environmental Issues

  • There are 11 NCERT questions in the 1st set in which you need to answer basic questions on the causes and effects of various means of pollution.
  • The 2nd set is MCQs with 20 questions. You need to apply your knowledge of what kind of pollutants are created by which process or material, CNG, biomagnifications, radioactive wastes, etc.
  • In the 3rd set, there are assertion-reason type questions with 10 statements. In each of them, you have to evaluate if the assertions and reasons match. Questions are based on Eutrophication, types of pollution, and global warming.
  • The 4th section has 34 questions where very short answers are to be provided. They cover topics like CNG, air prevention and control act, types of pollution, and ozone layer depletion.
  • In the 5th set, you have to give short answers to its 37 questions consisting of thermal power plants harmful effects, automobile and air pollution, water pollution, etc.
  • The 6th set has again short-type questions with a total of 19 questions in it. They touch on the following areas: global warming, BOD and water pollutants like algal bloom, Eutrophication. One question needs you to draw a flowchart of biomagnification in the aquatic food chain.
  • In the 7th set, you need to provide long answers for its 6 questions. Some highlights of these questions are solid waste management, chipko movement, scrubber usage, biomagnifications, and El Nino effect.
  • The 8th and the last section has 12 questions of varied types like MCQs, short and long answers, assertion-reason type touching key areas of the chapter.

Why Use Xam Idea Class 12 Biology Solutions Chapter 16: Environmental Issues by Instasolv?

  • Understanding your environment and what causes its degradation is a very important chapter in Biology from CBSE exam perspectives.
  • There are many ideas and terms involved in the chapter which need detailed explanations.
  • Our team does a lot of research before answering the Xam Idea questions so that you have the most reliable source at hand. 
  • The Xam Idea Class 12 Biology Solutions are framed with a clear flow of statements so that nothing seems confusing to you once you go through our solutions. 
  • Our Xam Idea Biology Solutions for Class 12 are free of cost hence there is nothing stopping you from learning and achieving good marks.