Tag: evs

Questions Related to evs

Which of the following is an example of crustose lichen?

  1. Parmelia

  2. Cladonia

  3. Usnea

  4. Graphis


Correct Option: D
Explanation:

Crustose lichen forms a thin crust growing on or in the substrate, and which cannot be detached from it. They may be areolate (divided into islands by cracks in the thallus). An upper cortex protects the algal layer in the medulla beneath, and there is often a differently coloured ring of actively growing fungal hyphae round the margin (the prothallus). Graphis is a crustose lichen.

Thus, the correct answer is option D.

Lichens are ecologically important because

  1. They are associated with mycorrhizal roots.

  2. They are association of algae and fungi.

  3. They are pioneers (earliest settlers on barren rocks) and pass xeric conditions successfully.

  4. They can grow in greatly polluted area.


Correct Option: C
Explanation:

Lichens are known as pioneer species, these can survive in places where higher plants finds it difficult to grow. Irrespective of the type of region, extremes in environmental conditions, mountainous terrains and high latitudes, lichens are good survivors. Besides these, the major ecological importance of the lichens are that these are poikilohydric. With little control over the status of hydration, these are able to tolerate irregular and even severe dessication. Thus, the correct answer is option C.

Select true statements.

  1. The whole surface of the lichen thallus helps absorption of water both in liquid and vapour form.

  2. In U.S.S.R. and Sweden, lichens were used in alcohol production because they contain the carbohydrate known as lichenin.

  3. Parmelia species are used as curry powder in India.

  4. All of the above.


Correct Option: D
Explanation:

Parmelia is a genus of the family Parmeliaceae is a medium to large foliose lichens. These grow in a wide range of shapes and forms and is usually determined by the organization of the fungal filaments. The vegetative body is called as the thallus which helps in absorbing water. The route from lichen to alcohol was first via a treatment with acid to transform lichenin (a carbohydrate) into glucose and during the Second World War, there was industrial production of sugar from lichens in Russia. The incentive to use lichens came from the scarcity of beet sugar and the need to use grain or potato starch for military alcohol production. 

Thus, the correct answer is option D.

Lichens can be used as 

  1. Bio-indicator for water and air pollution

  2. Initial vegetation for waste lands.

  3. Source of wood

  4. To check the air pollution


Correct Option: A
Explanation:

Lichens are mutualistic associations of a fungus and an alga or cyanobacterium. Lichens are very sensitive to sulphur dioxide pollution in the air. Lichens are sensitive to sulphur dioxide because their efficient absorption systems result in rapid accumulation of sulphur when exposed to high levels of sulphur dioxide pollution. The algal partner are most affected by the sulphur dioxide; chlorophyll is destroyed and photosynthesis is inhibited. Lichens also absorb sulphur dioxide dissolved in water. 

Lichens are widely used as environmental indicators or bio-indicators. If air is very badly polluted with sulphur dioxide there may be no lichens present. If the air is clean, shrubby, hairy and leafy lichens become abundant. 

Indicator plants which can be used to indicate atmospheric pollution by SO$ _2$ are 

  1. Lichens like Usnea

  2. Grassland like Deschampsia

  3. Moss like Sphagnum

  4. Climbers like Cucurbita


Correct Option: A
Explanation:

Lichens are mutualistic associations of a fungus and an alga or cyanobacterium and occur as crusty patches or bushy growths on trees, rocks and bare ground. Lichens are very sensitive to sulphur dioxide pollution in the air. Their efficient absorption systems result in rapid accumulation of sulphur when exposed to high levels of sulphur dioxide pollution. The algal partner is most affected by the sulphur dioxide; chlorophyll is destroyed and photosynthesis is inhibited. Lichens are widely used as environmental indicators or bio-indicators. If air is very badly polluted with sulphur dioxide, there may be no lichens present, just green algae may be found. If the air is clean, shrubby, hairy and leafy lichens become abundant. Thus, the correct answer is option A.

Which of the following is considered as primary source of water?

  1. Rainwater

  2. River water

  3. Pond water

  4. Groundwater


Correct Option: A
Explanation:

Rainwater is the primary source of water. Rain water is considered as a pure and fresh form of water.

The total percentage of fresh drinking water on earth is around:

  1. $0.3$%

  2. $10$%

  3. $25$%

  4. $40$%


Correct Option: A
Explanation:

On Earth, only 3% of water is fresh water. Most of the water is in the form of ice caps, glaciers and groundwater, while all lakes, rivers and swamps combined only for a very small part that is 0.3% of the earth's total freshwater reserves.

Which part of the water cycle includes in cloud formation?

  1. vaporisation

  2. condensation

  3. precipitation

  4. none of these


Correct Option: B
Explanation:

In the process of condensation very small water droplets from the atmospheric air come together and form clouds. The heavier the rain drops gets bigger the cloud gets.

Which of the following is the part of water cycle?

  1. evaporation

  2. condensation

  3. precipitation

  4. all of them


Correct Option: D
Explanation:

Evaporation: The sun evaporates some amount of water from different sources. Evaporation prepares the cycle for the next step, that is condensation. 
Condensation: The water vapour then condensed into clouds. These clouds further go to Precipitation. 
Precipitation: When the droplets in the clouds get too big they fall as rain, hail, snow, and sleet.

A large number of people draw water from:

  1. well

  2. tube wells

  3. hand pumps

  4. all of the above


Correct Option: D
Explanation:

A larger number of people drawn  water from all of the above natural sources i.e  wells, tube wells, hand pumps etc.