NCERT Solutions Class 12 Biology Chapter 16 Environmental Issues

NCERT Solutions Class 12 Biology Chapter 16 Environmental Issues. The NCERT solutions for Class 11 Mathematics have been made by Mathematics teacher of one of the best CBSE school in India. These NCERT solutions have been made to give detailed answers and expanations of the concepts as per NCERT which can be easily understood by the students. Refer to other links also to download mathematics NCERT solutions, worksheets, sample papers and Exemplar Solutions. 

Class 12 Biology

NCERT Solutions

Chapter 16 Environmental Issues

Question 1: What are the various constituents of domestic sewage? Discuss the effects of sewage discharge on a river.

Answer Domestic sewage is the waste originating from the kitchen, toilet, laundry, and other sources. It contains impurities such as suspended solid (sand, salt, clay), colloidal material (fecal matter, bacteria, plastic and cloth fiber), dissolved materials (nitrate, phosphate, calcium, sodium, ammonia), and disease-causing microbes. When organic wastes from the sewage enter the water bodies, it serves as a food source for micro- organisms such as algae and bacteria. As a result, the population of these micro- organisms in the water body increases. Here, they utilize most of the dissolved oxygen for their metabolism. This results in an increase in the levels of Biological oxygen demand (BOD) in river water and results in the death of aquatic organisms. Also, the nutrients in the water lead to the growth of planktonic algal, causing algal bloom. This causes deterioration of water quality and fish mortality.

Question 2: List all the wastes that you generate, at home, school or during your Trips to other places, could you very easily reduce? Which would be Difficult or rather impossible to reduce?

Answer Wastes generated at home include plastic bags, paper napkin, toiletries, kitchen wastes (such as peelings of vegetables and fruits, tea leaves), domestic sewage, glass, etc. Wastes generated at schools include waste paper, plastics, vegetable and fruit peels, food wrappings, sewage etc. Wastes generated at trips or picnics include plastic, paper, vegetable and fruit peels, disposable cups, plates, spoons etc. Yes, wastes can be easily reduced by the judicious use of the above materials. Wastage of paper can be minimized by writing on both sides of the paper and by using recycled paper. Plastic and glass waste can also be reduced by recycling and re-using. Also, substituting plastics bags with biodegradable jute bags can reduce wastes generated at home, school, or during trips. Domestic sewage can be reduced by optimizing the use of water while bathing, cooking, and other household activities. Non- biodegradable wastes such as plastic, metal, broken glass, etc are difficult to decompose because micro-organisms do not have the ability to decompose them.

Please click the link below to download NCERT Solutions Class 12 Biology Chapter 16 Environmental Issues.

 

Tags: 

 


Click to View or Download pdf file
Click for more Biology Study Material

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

Class 12 Board Exams Datesheet Announced

CBSE has announced the datesheet of the remaining class 12 board exams, see below:  

TV Channels for Students by CBSE

In enhancing the students studying part, the Government is planning to introduce one standard one channel plan. The lockdown in India has adversely collapsed all the operations including schools, colleges, and workplaces with unanticipated setbacks. On behalf of the...

Checking of Boards Answer sheets starts today

CBSE has instructed almost 3000 schools to start the evaluation work for class 10th and class 12th board exam answer sheets from today. The checking of answer sheets for class 10th and class 12th was stopped earlier due to covid crisis in the country. Now in order to...

CBSE Board Exams in July Press Release

CBSE has released press note for the dates for the CBSE Board exams for Class 10. CBSE said “With regards to conduct of Class X examinations several queries are being received by the CBSE. In this context, it is once again reiterated that remaining examinations of...

CBSE Boards Answer Sheet Evaluation Class 10 and Class 12

HRD Minister Ramesh Pokhriyal, through a video conference with all the education ministers of the state, discussed the further steps to be taken to smoothen the education process during the Covid-19 lockdown. The most important topic which was discussed repeatedly on...

Board Exams Class 10 and 12 Notification by CBSE

Because of the prevailing condition of spread of COVID-19 pandemic in the country, special efforts are required for conducting examinations in a safe manner. As a number of students have shifted from the district of their school to some other district in the country,...

×
Studies Today