Environmental Biology MCQ Quiz in मल्याळम - Objective Question with Answer for Environmental Biology - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

The correct answer is China.

 Key Points

• The ecological footprint is the only metric that measures how much nature we have and how much nature we use.
• The ecological footprint adds up all the productive areas for which a population, a person or a product competes.
• It measures the ecological assets that a given population or product requires to produce the natural resources it consumes (including plant-based food and fibre products, livestock and fish products, timber and other forest products, and space for urban infrastructure) and to absorb its waste, especially carbon emissions. 
• China's physical quantity of ecological footprint in 2018 was 4.03 gha.
• China had the largest total ecological footprint of any country because of its huge population.

Therefore, the correct answer is China.

The correct answer is High.

 Key Points

• Early successional communities are those that establish themselves relatively quickly after disturbance, while late successional communities are those that establish themselves much later.
• Early successional systems tend to have smaller plant biomass, shorter plant longevity, faster rates of soil nutrient consumption, a reduced role for decomposer organisms, more open and rapid biogeochemical cycling, higher rates of net primary productivity, lower stability, and lower diversity than late successional systems.
• Early successional plants tend to have high rates of photosynthesis and respiration, high rates of resource uptake, and high light compensation points.
• Transpiration rates are generally high in early successional plants.

Therefore, the correct answer is high. 

The correct answer is Tundra vegetation.

 Key Points

Tundra:

• The tundra is the coldest of all the biomes with an annual average temperature of less than 5°C, and precipitation (mostly in the form of snow) of less than 100 mm per year.
• The weather conditions in the tundra are so harsh that only a handful of plants and animals can even survive there. 
• Due to extremely cold temperatures, the layer just below the surface remains permanently frozen.
• This frozen layer of ground is called permafrost. 

Desert:

• Deserts cover about one-fifth of the Earth's surface and occur where rainfall is less than 50 cm/year.
• Temperatures exhibit daily extremes because the atmosphere contains little humidity to block the Sun's rays.
• Desert surfaces receive a little more than twice the solar radiation received by humid regions and lose almost twice as much heat at night.
• Mean annual temperatures range from 20-25° C.
• The extreme maximum ranges from 43.5-49° C. Minimum temperatures sometimes drop to -18° C.

Taiga:

• Mean annual temperatures in the taiga range from a few degrees Celsius above freezing to −10 °C (14 °F) or more.
• Areas with a mean annual temperature below freezing are susceptible to the formation of permafrost soils.
• Areas of the taiga located in the centre of continents generally receive 30 to 50 cm (12 to 20 inches) of annual precipitation. 

Shrubland:

• The average annual rainfall in the shrublands is between 200 to 1,000 millimetres.
• The summers are hot and dry, while the winters are cool and moist.  
• The average annual temperature is 17° C and can reach up to 37.7° C in the summer and stays around 10° C during the winter.  

​Therefore, the correct answer is Tundra vegetation.

The correct answer is All of the above.

Key Points

The following four categories of ecotechnology may serve as the foundation for ecological engineering:

1. Ecosystems are used to reduce or solve a pollution problem that otherwise would be (more) harmful to other ecosystems. A typical example is the use of wetlands for wastewater treatment.
2. Ecosystems are imitated or copied to reduce or solve a pollution problem, leading to constructed ecosystems. Examples are fishponds and constructed wetlands for treating wastewater or diffuse pollution sources.
3. The recovery of ecosystems after significant disturbances. Examples are coal mine reclamation and restoration of lakes and rivers.
4. The use of ecosystems for the benefit of humanity without destroying the ecological balance (i.e., the utilization of ecosystems on an ecologically sound basis). Typical examples are the use of integrated agriculture and the development of organic agriculture; this type of ecotechnology finds wide application in the ecological management of renewable resources.

Since all statements regarding ecotechnology are correct. Therefore, the correct option should have been all of the above only.

The correct answer is Frankia.

Key Points

• Frankia is a gram-positive species of filamentous actinomycete capable of nitrogen fixation. It establishes root-nodule symbiosis with actinorhizal plants such as Alnus or Casuarina trees, where bacterial nitrogen fixation takes place.
• It can fix nitrogen in inhospitable environmental conditions such as mine locations and degraded and reclaimed lands, and the range of N₂ fixation is 2–300 kg N ha⁻¹ year⁻¹. 
• Frankia is a genus of soil actinomycetes in the family Frankiaceae that fix nitrogen both under symbiotic and free-living aerobic conditions.

Therefore, Frankia is the N-fixing actinomycete that is associated with higher plants.

Additional Information

• Clostridium is a genus of gram-positive, spore forming bacteria belonging to the family Clostridiceae. The majority of the species are obligate anaerobs, however, some species can grow under aerobic conditions or are aerotolerant.
• Among nitrogen-fixing organism, the genus Clostridium occupies a very special place.
• The species Clostridium pasteurianum is the first known free-living nitrogen-fixing bacteria.
• Anabaena is a plankton-forming genus of flilamentous cynobacteria. They are noted for their nitrogen-fixing ability and their symbiotic relationship with plants like mosquito fern.
• Azospirillum is a gram-negative, microaerophilic, non-fermentative and nitrogen-fixing bacterial genus from the family of Rhodospirillaceae. 
• Azospirillum bacteria can promote plant growth.

The correct answer is 'Pseudomonas putida'

Key Points

• Pseudomonas putida:
  • Pseudomonas putida is a Gram-negative, rod-shaped bacterium known for its ability to degrade a wide variety of organic pollutants, including hydrocarbons found in oil.
  • It has been genetically enhanced to improve its biodegradation capabilities, earning it the nickname "superbug."
  • This bacterium can degrade toxic compounds such as toluene, xylene, and camphor, converting them into harmless substances.
  • The enhanced strains of Pseudomonas putida are used in bioremediation efforts to clean up oil spills and contaminated environments, particularly in marine and soil ecosystems.
  • Its metabolic versatility makes it an invaluable microorganism in environmental biotechnology.

Additional Information

• Rhodococcus:
  • Rhodococcus is another genus of bacteria known for its ability to degrade a wide range of hydrocarbons, including those found in oil pollutants.
  • Species like Rhodococcus erythropolis are used in bioremediation to break down complex organic pollutants, though they are not specifically referred to as "superbugs."
• Mycobacterium:
  • Although species of Mycobacterium are known for their roles in human diseases (e.g., tuberculosis), some environmental mycobacteria have been studied for their ability to degrade hydrocarbons.
  • However, they are not as commonly used or as efficient as Pseudomonas putida in the context of bioremediation.
• Sphingomonas:
  • Sphingomonas species are also capable of degrading various environmental pollutants, including some hydrocarbons and aromatic compounds.
  • These bacteria are significant in bioremediation but are not typically referred to as "superbugs" due to their less extensive use compared to Pseudomonas putida.

Important Points

• Superbugs like Pseudomonas putida are genetically engineered to enhance their natural capabilities, making them more effective at breaking down harmful pollutants.
• Bioremediation using such microorganisms is a promising and eco-friendly method to address environmental contamination, reducing the reliance on chemical treatments.
• The term "superbug" in this context is positive, referring to the enhanced environmental cleanup capabilities, unlike its use in medicine where it often refers to antibiotic-resistant pathogens.

The correct answer is: A, B and D only

Key Points

• Extend from the boundary of continental shelf to the deepest oceans:
  • This statement is correct.
  • Deep open benthos communities are found from the continental shelf boundary to the deepest parts of the oceans, typically beyond the reach of light penetration.
• Often are entirely heterotrophic living on and in mud surface and bacteria:
  • This statement is correct.
  • These communities largely consist of heterotrophic organisms, which depend on organic material that falls from above or is decomposed by bacteria in the sediment.
• Include plankton and large swimming animals:
  • This statement is incorrect.
  • Plankton and large swimming animals are typically part of the pelagic zone, not the benthos. Benthos refers to organisms that live on, in, or near the ocean floor.
• Are rich in biodiversity through strange, occupying permanent cold and dark water:
  • This statement is correct.
  • Deep-sea benthos communities are notable for their strange and diverse forms of life that have adapted to the cold, dark, high-pressure environment.
• Are nutrient-rich water supporting growth of organisms:
  • This statement is incorrect.
  • Deep-sea benthos environments are usually low in nutrients because they rely on material falling from the more productive surface layers of the ocean. The water itself is not rich in nutrients.

Additional Information

• Benthos Community:
  • Benthos refers to organisms living on, in, or near the ocean floor, including the deepest parts of the oceans.
  • These communities have specialized adaptations to survive in various environmental conditions, from continental shelves to abyssal plains.
• Nutrient Dynamics:
  • Deep-sea ecosystems depend on the "marine snow" – organic material falling from the upper layers of the ocean – for nutrients.
  • Upwelling zones, where deep, nutrient-rich water reaches the surface, are more likely to offer nutrient-rich environments compared to deep benthos regions.
• Diversity in Deep-sea Benthos:
  • The extreme conditions of deep-sea benthos habitats lead to unique forms of biodiversity, including bioluminescent organisms and extremophiles that can endure high pressure and low temperatures.

The correct answer is Statement I is true but Statement II is false.  

Key Points

• Nitrogen enters the living world by way of bacteria and other single-celled prokaryotes, which convert atmospheric nitrogen, N₂ into biologically usable forms in a process called nitrogen fixation. 
• Nitrogen-fixing microorganisms capture atmospheric nitrogen by converting it to ammonia, NH₃ which can be taken up by plants and used to make organic molecules.

Thus the statement I is true.

• Nitrogen doesn't remain forever in the bodies of living organisms.
• Instead, it's converted from organic nitrogen back into N₂ gas by bacteria.
• This process often involves several steps in terrestrial—land—ecosystems.
• Nitrogenous compounds from dead organisms or wastes are converted into ammonia, NH₃ by bacteria, and ammonia is converted into nitrites and nitrates.
• In the end, the nitrates are made into N₂ gas by denitrifying prokaryotes.

Thus statement II is false.

Therefore, the correct answer is that statement I is true but statement II is false.  

The correct answer is A change occurring at a steady rate where the rate is defined by the directions of change.

 Key Points

• Hysteresis is observed following a perturbation to an equilibrium point when the return trajectory to the original equilibrium point or state is different from the outgoing trajectory.
• In ecological terms, this often means that the work that must be done to return to an original state after a disturbance is much more than the work done by the original perturbation itself.
• Hysteresis is a characteristic of alternative stable states.
• It can be used to identify their presence because it means that more than one state can be observed under identical environmental conditions — at least over some range of conditions. 
• Here the perturbation occurs at a steady rate and that rate is dependent on the direction of change i.e., either positive or negative.

Therefore, the correct answer is a change occurring at a steady rate where the rate is defined by the directions of change.

The correct answer is comparing the relative degree of tolerance of an organism to a given environmental factor.

 Key Points

• The prefix "steno" and "eury" have been used for comparing the relatively narrow and wide degree of tolerance, respectively of an organism to a given environmental factor.
• Examples:
  • Stenohydric and euryhydric refer to narrow and wide tolerance respectively to water.
  • Stenohaline and euryhaline refer to narrow and wide tolerance respectively to salinity.
  • Stenophagic and euryphagic refer to narrow and wide tolerance respectively to food.
  • Stenoecious and euryoecious refer to narrow and wide tolerance respectively to habitat selection.
  • Stenothermal and eurythermal refer to narrow and wide tolerance respectively to temperature.

Therefore, the correct answer is comparing the relative degree of tolerance of an organism to a given environmental factor.