12th Botany - Book Back Answers - Chapter 8 - English Medium Guides

 

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Tamil Nadu Board 12th Standard Botany - Chapter 8: Book Back Answers and Solutions

    This post covers the book back answers and solutions for Chapter 8 – Botany from the Tamil Nadu State Board 12th Standard Botany textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.

    We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.

    By going through this material, you’ll gain a strong understanding of Botany Chapter 8 along with the corresponding book back questions and answers (PDF format).

Question Types Covered:

• 1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following 
• 2 Mark Questions: Answer briefly 
• 3, 4, and 5 Mark Questions: Answer in detail

All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.

All the best, Class 12 students! Prepare well and aim for top scores. Thank you!

Unit 8 - Environmental Issues

I. Multiple Choice Questions

1. Which of the following would most likely help to slow down the greenhouse effect. 
a) Converting tropical forests into grazing land for cattle. 
b) Ensuring that all excess paper packaging is buried to ashes. 
c) Redesigning landfill dumps to allow methane to be collected. 
d) Promoting the use of private rather than public transport.
Answer Key:
c) Redesigning landfill dumps to allow methane to be collected. 

2. With respect to Eichhornia 
Statement A: It drains off oxygen from water and is seen growing in standing water. 
Statement B: It is an indigenous species of our country. 
a) Statement A is correct and Statement B is wrong. 
b) Both Statements A and B are correct. 
c) Statement A is correct and Statement B is wrong. 
d) Both statements A and B are wrong.
Answer Key:
a) Statement A is correct and Statement B is wrong. 

3. Find the wrongly matched pair. 
a) Endemism - Species confined to a region and not found anywhere else. 
b) Hotspots - Western ghats 
c) Ex-situConservation - Zoological parks 
d) Sacred groves - Saintri hills of Rajasthan 
e) Alien sp.Of India - Water hyacinth
Answer Key:
d) Sacred groves - Saintri hills of Rajasthan 

4. Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancer? 
a) Ammonia 
b) Methane 
c) Nitrous oxide 
d) Ozone
Answer Key:
d) Ozone

5. One green house gas contributes 20% of total global warming and another contributes 60%. These are respectively identified as 
a) N2O and CO2 
b) CFCs and N2O 
c) CH4 and CO2 
d) CH4 and CFCS
Answer Key:
c) CH4 and CO2 

6. One of the chief reasons among the following for the depletion in the number of species making endangered is 
a) over hunting and poaching 
b) green house effect 
c) competition and predation 
d) habitat destruction
Answer Key:
d) habitat destruction

7. Deforestation means 
a) growing plants and trees in an area where there is no forest 
b) growing plants and trees in an area where the forest is removed 
c) growing plants and trees in a pond 
d) removal of plants and trees
Answer Key:
d) removal of plants and trees

8. Deforestation does not lead to 
a) Quick nutrient cycling 
b) soil erosion 
c) alternation of local weather conditions 
d) Destruction of natural habitat weather conditions
Answer Key:
a) Quick nutrient cycling

9. The unit for measuring ozone thickness 
a) Joule 
b) Kilos 
c) Dobson 
d) Watt
Answer Key:
c) Dobson

 

10. The lake which was built in British era and is near the Indian Army Base
a) Veeranam lake
b) Maduranthagam lake
c) Sholavaram lake
d) Chembrambakkam lake

Answer Key:

c) Sholavaram lake 

11. People’s movement for the protection of environment in Sirsi of Karnataka is 
a) Chipko movement 
b) Amirtha Devi Bishwas movement 
c) Appiko movement 
d) None of the above
Answer Key:
c) Appiko movement 

 

12. The invasive species introduced in India from South America
a) Lantana 

b) Prosopis
c) Parthenium 

d) Kappaphycus

Answer Key:
a) Lantana 

 
13. The plants which are grown in silivpasture system are 
a) Sesbania and Acacia 
b) Solanum and Crotalaria 
c) Clitoria and Begonia 
d) Teak and sandal
Answer Key:
a) Sesbania and Acacia 

 

14. IUCN red list categories has developed criteria for threatened species. The criteria ‘C’ refers to
a) Geographic range
b) Quantitiative analysis
c) Small population size and decline
d) population reduction

Answer Key:

d) population reduction 

  

II. Short Answer Questions

12th bio botany

III. Long Answer Questions

12th bio botany

IV. Exercise

12thbio botany