Students get through the TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues which is useful for their exam preparation.

TN State Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Very short answer questions

Question 1.
Define the greenhouse effect.
Answer:
The greenhouse effect is defined as a process by which the radiant heat from the sun is captured by gases in the atmosphere, leading to an increase in atmospheric temperature.

Question 2.
Define global warming.
Answer:
Global warming is a process through which the mean global temperature increases due to the increased concentration of greenhouse gases.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 3.
Mention any two natural sources of methane in the atmosphere.
Answer:

  1. Paddy fields
  2. Bacterial action in water bodies.

Question 4.
Expand CDM.
Answer:
CDM means Clean Development Mechanism.

Question 5.
Mention any two plants which can indicate SO2 pollution.
Answer:

  1. Ficus
  2. Pinus

Question 6.
What do you mean by social forestry?
Answer:
Social forestry refers to the management of forest and afforestation on barren lands with the purpose of helping the environmental, social, and rural development and benefits.

Question 7.
Mention any two causes of Deforestation.
Answer:

  1. Agriculture plantation and livestock ranching are one of the main causes of deforestation.
  2. Disproportionate felling of trees for timber.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 8.
Define Alien species.
Answer:
Alien species is defined as a non-native species to the ecosystem on the country, which poses a serious threat to the native species and ecosystem.

Question 9.
Name any two invasive plant species in India.
Answer:
The invasive plant species are:

  1. Prosopis juliflora
  2. Eichhornia crassipes.

Question 10.
Define Endemic species.
Answer:
Endemic species are defined as plants or animals that exist only in one geographic region.

Question 11.
Define carbon sequestration.
Answer:
Carbon sequestration is defined as a process through which capturing and storing of carbon-di-oxide in the atmosphere take place.

Question 12.
What is Biochar?
Answer:
Biochar is a long-term method to increase the ability of plants to store more carbon.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 13.
Expand EIA.
Answer:
EIA means Environmental Impact Assessment.

Short answer questions

Question 1.
Explain briefly about remote sensing.
Answer:
Remote sensing is the acquisition of information about an object without making physical contact with the object by measuring its reflected and emitted radiation at a distance from the target area. It gives exact pictures and data on the identification of even a single tree in a large area of vegetation and wildlife. It is also helpful in the identification of biodiversity-rich or fewer areas for futuristic works on conservation and restoration of biota. It helps in the maintenances of various species including commercial crops, medicinal plants, and threatened plants.

Question 2.
What is biomonitoring? Explain it briefly.
Answer:
Biomonitoring is the act of observing and assessing the current state and changes in the ecosystem, biodiversity components, landscape including natural habitat, population, and species. Eg: In an agricultural drone, a bird’s eye view of a farmer can reveal many issues like irrigation problems, soil variation, and pests as well as fungal infestation. It is used in farming in order to help increased crop production and monitor crop growth. It is also helpful for a cost-effective safe methods of spraying pesticides and fertilizer.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 3.
Invasion of alien species disrupts ecosystem processes. Justify.
Answer:
The alien species disrupt ecosystem processes, because

  1. They threaten biodiversity, reduce native herbs, reducing ecosystem services (benefits).
  2. They only alter the ecosystem and micro intimate by prolific spreading.
  3. They also alter the nature of the soil and make it unsuitable for native species.
  4. They create human health problems like allergies.
  5. Thus they degrade the local environment and eliminate important local species.

Question 4.
Mention any three achievements of the Afforestation project.
Answer:

  1. Degraded forests were restored.
  2. Environmental and ecological stability was maintained.
  3. Afforestation was helpful to conserve bio-diversity, wildlife, and genetic resources.

Question 5.
Distinguish between Agroforestry and social forestry.
Answer:

Agroforestry Social forestry
Agroforestry is an integration of trees crops and livestock on the same piece of land. Social forestry refers to the management of forests and afforestation on barren lands.
Main objective of this is to build interaction among above components. Main objective includes helping environmental, social and rural development and their benefits.
Intercropping of two or more crops between different species of trees and shrubs resulting in higher yield and reduction in operation cost. Social forestry programme is carried out for the benefit of people and participation of people in order to reduce pressure on forest.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 6.
Mention any three major activities of forestry extension centers.
Answer:

  1. Imparting training to the public on tree growing methods.
  2. Publicity and propaganda of the advantage of tree growing,
  3. Raising the seedlings of important tree species and supply to the public with subsidies.

Question 7.
Write down any three effects of- global warming on plants.
Answer:

  1. Global warming leads to low agricultural productivity.
  2. Weeds, pests, and fungi which need warmer temperature, will increase in number due to global warming.
  3. Global warming may change the flowering seasons and pollinators.

Question 8.
Mention any three causes of greenhouse gas emission.
Answer:

  1. Agriculture practices and animal husbandry practices lead to the emission of CH4.
  2. CO2 and CH4, are produced by burning fossil fuels.
  3. The household items like electrical gadgets including refrigerators and air conditioners release chlorofluorocarbon.

Long answer questions

Question 1.
List the objectives of Afforestation:
Answer:

  1. One of the prime objectives of Afforestation is to increase forest cover by planting more trees, which increases O2 production and air quality.
  2. Rehabilitation of degraded forests to increase CO2 fixation, leading to reduction of atmospheric carbon dioxide.
  3. Medicinal plants are planted in mixed plantations and produce natural medicines.
  4. Regeneration of indigenous herbs and shrubs.
  5. The other objectives include the increase of availability of water table or groundwater, reduction of nitrogen leaching from the soil, and reduction of nitrogen contamination of drinking water.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 2.
List the plants used as plant indicators of pollutions.
Answer:

Plants Indicator for pollutants
Ficus, Lichens, Pinus, and Rose. SO2 Pollution.
Petunia and Chrysanthemum Nitrate contamination.
Gladiolus Fluoride pollution.
Robinia pseudo­acacia (Black locust tree) Indicator of heavy metal contamination.

Question 3.
Distinguish between in-situ and ex-situ conservation.
Answer:

In-situ Conservation Ex-situ conservation
In insitu conservation, the conservation of management of genetic resources in their natural habitats In ex-situ conservation the species are protected outside their natural environment.
In this method, forest trees, medicinal and aromatic plants under thread are conserved within the existing habitat. The plants are conserved is botanical gardens, and following some of conservation strategies like gene, pollen, seed in-vitro conservation cryo preservation, seedling, tissue culture and DNA banks.

Question 4.
Write about Biodiversity impact Assessment. How will you assess the impact?
Answer:
Biodiversity Impact Assessment (BIA) can be defined as a decision-supporting tool to help the development considering bio-diversity as an inclusive component followed by planning and implementation.
It integrates biodiversity consideration for developmental proposals.
They are legally bound mechanisms for implementing the conservation of biodiversity resources. They also provide fair and equitable sharing of the benefits arising from the use of bio-diversity.
The Bio-diversity impacts can be assessed by:

  1. Change in land use and cover.
  2. Fragmentation and isolation.
  3. Extraction.
  4. External inputs such as emissions, effluents, and chemicals.
  5. Introduction of invasive, alien, or genetically modified species.
  6. Impact on endemic and threatened flora and fauna.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

Question 5.
List the importance of GIS.
Answer:

  1. GIS is used in Environmental Impact Assessment.
  2. It is also helpful in disaster management.
  3. It is used in the zoning of landslide hazards.
  4. It helps in the determination of land cover and land use.
  5. It is used to determine flood damage.
  6. It is used in the management of natural resources.
  7. Soil mapping and wetland mapping can be done using GIS.
  8. Identification of volcanic hazards and irrigation management can be carried out by this information.
  9. It helps to study vegetation and to map threatened and endangered species.

Activity

Students may form ‘ECOGROUPS’ and discuss eco-issues of their premises and find solutions to the existing problems like litter disposal, water stagnation, health, and hygiene, greening the campus, and its maintenance.
Eco groups discussion topics:

  1. Litter disposal: The litter forms solid waste which includes degradable and non-degradable waste. The degradable waste can be degraded to manure using bacteria and earthworms. Non- degradable waste like plastic can be recycled.
  2. Water stagnation: Solution: Setting up of water harvesting system will solve water stagnation.
  3. Health and hygiene: Solution: Keep the surroundings clean and neat. Follow personal hygiene strictly. Create awareness among the public.
  4. Greening the campus: Solution: A tree planting programme may be initiated in the campus. Each member of Eco groups may be given responsibility for maintaining one or two trees in the campus.

Multiple choice questions

1. Match the following.
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 1
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iii); (q)-(iv); (r)-(ii); (s)-(i)
(c) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
(d) (p)-(iv); (q)-(i); (r)-(ii); (s)-(iii)
Answer:
(b) (p)-(iii); (q)-(iv); (r)-(ii); (s)-(i)

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

2. Match the following.
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 2
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iv); (q)-(iii); (r)-(i); (s)-(ii)
(c) (p)-(iv); (q)-(i); (r)-(ii); (s)-(iii)
(d) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
Answer:
(c) (p)-(iv); (q)-(i); (r)-(ii); (s)-(iii)

3. Match the following.
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 3
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iv); (q)-(iii); (r)-(i); (s)-(ii)
(c) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
(d) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
Answer:
(b) (p)-(iv); (q)-(iii); (r)-(i); (s)-(ii)

4. Match the following.
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 4
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iv); (q)-(iii); (r)-(i); (s)-(ii)
(c) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
(d) (p)-(iii); (q)-(iv); (r)-(ii); (s)-(i)
Answer:
(d) (p)-(iii); (q)-(iv); (r)-(ii); (s)-(i)

5. Choose the odd man out.
(a) Sudhir kumar Sopary.
(b) Jadav molai Payeng
(c) Panduranga Hegde
(d) Swaminathan
Answer:
(d) Swaminathan

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

6. Find out the odd one.
(a) Western ghat
(b) National park
(c) Gulf of mannar
(d) Agasthiar malai
Answer:
(c) Gulf of mannar

7. Indicate the odd one (Ex-situ conservation)
(a) Pollen
(b) Seed
(c) Seedling
(d) Leaf
Answer:
(d) Leaf

8. Choose the odd one:
(a) Carbon-di-oxide
(b) Ammonia
(c) Methane
(d) Nitrous oxide
Answer:
(b) Ammonia

9. Choose the incorrect pair.
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 5
Answer:
(c)

10. Choose the incorrect pair?
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 6
Answer:
(d)

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

11. Which of the following is a correct pair?
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 7
Answer:
(a)

12. Choose the incorrect pair:
TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues 8
Answer:
(c)

13. Find out the plant indicator. depletion.
(a) Water Lilly
(b) Coconut
(c) Acacia sp
(d) Gladiolus
Answer:
(d) Gladiolus

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

14. Ozone depletion in the atmosphere results in:
(a) UV radiation
(b) CO2 emission
(c) Nitrogen depletion
(d) Afforestation
Answer:
(a) UV radiation

15. Which of the following is a hedge plant.
(a) Azadirachta indica
(b) Acacia spp
(c) Teak
(d) Eucalyptus
Answer:
(b) Acacia spp

16. Alien invasive species include.
(a) Casuarina
(b) Amelia dubia correct.
(c) Prosopis juliflora
(d) Bamboo
Answer:
(c) Prosopis juliflora

17. Assertion: Majority of endemic species are threatened.
Reason: Because of their narrow specific habitat, reduced seed production low dispersal rate, less viable nature and human interference.
(a) Both Assertion and Reason are correct, Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, Reason is not the correct explanation of Assertion.
(c) Assertion is correct, Reason is not correct.
(d) Both Assertion and Reason are not correct.
(e) Assertion is not correct, Reason is correct.
Answer:
(a) Both Assertion and Reason are correct, Reason is the correct explanation of Assertion.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

18. Assertion: Eichhornia crassipes increases the oxygen content of water bodies.
Reason: Anoxic condition in water bodies leads to Eutrophication.
(a) Both Assertion and Reason are correct, Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, Reason is not the correct explanation of Assertion.
(c) Assertion is correct, Reason is not correct.
(d) Both Assertion and Reason are not correct.
(e) Assertion is not correct, Reason is correct.
Answer:
(e) Assertion is not correct, Reason is correct.

19. Assertion: In plants, photosynthetic chemicals will be affected due to ozone depletion.
Reason: Decreased photosynthesis will result in increased atmospheric CO2, resulting in global warming.
(a) Both Assertion and R are correct, R is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, Reason is not the correct explanation of Assertion.
(c) Assertion is correct, Reason is not correct.
(d) Both Assertion, and Reason are not correct.
(e) Assertion is not correct, Reason is correct.
Answer:
(b) Both Assertion and Reason are correct, Reason is not the correct explanation of Assertion.

20. Assertion: In Agroforestry, nutrient cycling between species improves and organic matter in the soil is maintained.
Reason: Because of the absence, of microorganisms, insects, and earthworm in the soil.
(a) Both Assertion and Reason are correct, Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are Correct, Reason is not the correct explanation of Assertion.
(c) Assertion is correct, Reason is not correct
(d) Both Assertion and Reason are not correct.
(e) Assertion is not correct, Reason is correct.
Answer:
(c) Assertion is correct, Reason is not correct

21. Which of the following statement is correct?
(a) Trees provide microclimate for crops.
(b) They disturb O2-CO2 balance.
(c) Trees increase atmospheric CO2.
(d) Trees cause decrease in relative humidity in atmosphere.
Answer:
(a) Trees provide microclimate for crops.

TN Board 12th Bio Botany Important Questions Chapter 8 Environmental Issues

22. Choose the incorrect statement.
(a) Ozone depletion increases the incidence of cataract in human.
(b) It also causes lung irritation.
(c) Ozone depletion enhances the functioning of immune system.
(d) It increases the incidence of mutation:
Answer:
(c) Ozone depletion enhances the functioning of immune system.

23. Find out the correct statement.
(a) Prosophis juliflora is a native species found in Tamil Nadu.
(b) It is an aggressive coloniser.
(c) It is an invasive species native of South Africa.
(d) None of the above.
Answer:
(b) It is an aggressive coloniser.

24. Indicate the incorrect statement.
(a) Hardwickia binata is an endemic tree.
(b) It is endemic to peninsular and northern India.
(c) It is endemic to Kerala and Tamil Nadu.
(d) None of above.
Answer:
(c) It is endemic to Kerala and Tamil Nadu.