Ecology and Environment MCQ Quiz - Objective Question with Answer for Ecology and Environment - Download Free PDF

The correct answer is 1 to 2 weeks.

Key Points

• Peels of vegetables and fruits, leftover food items, all these are called organic waste.
• Organic Waste -
  • Due to the very fast (one to two weeks) action of bacteria on such waste, it gets decomposed quickly and mixes in soil, water, and air.
  • It does not cause any kind of pollution.
  • Agricultural waste, crop plants, peels of fruits and vegetables, dry leaves and wood, feces, urine, etc. are organic waste.
  • Compost and biogas can be made from organic waste.

Additional Information

• ​Non-organic wastes -
  • Bacterial action on such waste is slow.
  • Some substances take hundreds of years to decompose, such as glass, plastic, polythene, etc.
  • These substances remain in the environment for a long time and produce toxic substances in the environment.

The correct answer is Sanctuary.

• The boundaries in biosphere reserves and national park are defined by legislation.
• Whereas the boundaries of wildlife sanctuaries are not demarcated by the authorities.

Wildlife Sanctuary:

• This is a conservation area dedicated to the conservation of a particular species.
• In wildlife sanctuaries, human activities such as grazing, cutting of trees, timber collection etc is allowed.
• The state governments are authorised to notify a forest area as a wildlife sanctuary.

National Parks:

• The conservation scope of national parks is wider than that of wildlife sanctuaries.
• The national parks aim to conserve biotic as well as abiotic components of a landscape.
• Human activities are not permitted in the core area of national parks but limited activities like tourism are allowed outside the core area.
• The state government can notify a wildlife sanctuary or other reserve forest as a national park under the Wildlife Protection Act 1972.

Biosphere Reserve:

• Biosphere reserves are the largest conservation areas and may comprise of more than one national parks and wildlife sanctuaries.
• The biosphere reserves are notified by the central government under UNESCO's Man and Biosphere (MAB) programme.
• A biosphere reserve has a Core Area, a Buffer Zone and a Transition Zone.
• Human activities are strictly prohibited in the core area, in buffer zone activities like tourism, research and grazing can be carried out.
• In the transition zone, human settlements are also allowed. 

The correct answer is 'Water vapor, carbon dioxide, methane, nitrous oxide, ozone'.

Key Points

Greenhouse Gases

• Greenhouse gases are responsible for the greenhouse effect.
• These gases absorb and emit energy within the thermal infrared range.
• The primary greenhouse gases include carbon dioxide, methane, ozone, and water vapors.
• While the secondary greenhouses are Sulfur dioxide as well as nitrous oxides.
• The vibrations of any gas molecule such as oxygen tend to be invisible to the electromagnetic field.
• It does not absorb infrared light, in other words, it is not infrared active.
• Hence, oxygen is not a greenhouse gas as it is transparent to infrared light.

The correct answer is All of the above.

Key Points

• Several factors can contribute to the spread of a wildfire, including wind, topography, and humidity. Wind can spread the fire by carrying embers and heat to new areas, while topography, such as hills or canyons, can create natural wind tunnels that accelerate the spread of the fire. Low humidity can cause vegetation to dry out, making it more combustible and easier to ignite.
• High atmospheric temperatures and dryness (low humidity) offer favorable circumstances for a fire to start.
• In a natural setting, such as a forest, grassland, brushland, or tundra, any uncontrolled and non-prescribed combustion or burning of plants that consume the available fuels and spreads as a result of environmental factors (such as wind, and topography) is known as a bushfire, vegetation fire, or wildfire.
• For a wildfire to start and spread, the following three factors must be true: a source of heat, fuel, and oxygen.

Additional Information 

Types of Forest Fire:

There are three basic types of wildfires:

• Crown fires burn trees up their entire length to the top. These are the most intense and dangerous wildland fires.
• Surface fires burn only surface litter and duff. These are the easiest fires to put out and cause the least damage to the forest.
• Ground fires (sometimes called underground or subsurface fires) occur in deep accumulations of humus, peat, and similar dead vegetation that become dry enough to burn. These fires move very slowly but can become difficult to fully put out, or suppress.

Environmental protection refers to the practice of safeguarding the natural environment and its resources from degradation, pollution, overexploitation, and other detrimental impacts caused by human activities.

Key Points

•  The goal is to ensure the sustainable use of natural resources, preserve biodiversity, and maintain the overall health and balance of ecosystems.
• Environmental protection involves adopting measures to minimize pollution, conserve energy, manage waste responsibly, protect endangered species, and promote sustainable practices in industries, agriculture, and daily life.
• It also emphasizes the importance of environmental awareness, education, and policies to address global challenges like climate change and loss of biodiversity.

The correct answer is i - b, ii - c, iii - d, iv - a.

Key Points

The trophic levels represent the hierarchical levels in an ecological food chain, indicating the position of organisms based on their feeding relationships. Here's the explanation for the correct match:

• First trophic level - phytoplankton:
  • The first trophic level typically consists of primary producers that convert sunlight into energy through photosynthesis.
  • Phytoplankton are microscopic plants that form the base of aquatic food chains.
• Second trophic level - zooplankton:
  • The second trophic level comprises primary consumers that feed on the primary producers.
  • Zooplankton, which includes tiny animals, consume phytoplankton, placing them at the second trophic level.
• Third trophic level - fishes:
  • The third trophic level involves secondary consumers that feed on primary consumers.
  • In aquatic ecosystems, fishes are often positioned at the third trophic level as they consume zooplankton or other smaller organisms.
• Fourth trophic level - human:
  • The fourth trophic level represents tertiary consumers, which are higher-order predators.
  • Humans, being omnivores or carnivores, are often placed at the fourth trophic level in food chains when they consume animals from lower trophic levels.​ 

The correct answer is Cow.

Key Points

• Food chain: 
  • A food chain shows the feeding relationship between different organisms in a particular environment and/or habitat.
  • A food chain shows how energy is passed from the sun to producers, from producers to consumers, and from consumers to decomposes such as fungi. 
  • They also show how animals depend on other organisms for food.
  • In a food chain of Grass > Cow > wolf > Tiger, the frog occupies the third trophic level as it eats insects and further becomes the food for the snake.
• Tropic level: 
  • Based on the source of their nutrition or food, organisms occupy a specific place in the food chain that is known as their trophic level.
  • Producers belong to the first trophic level, herbivores (primary consumers) to the second, and carnivores (secondary consumers) to the third. The important point to note is that the amount of energy decreases at successive trophic levels.
  • Primary producers are at the first tropic level - They produce food on their own with the help of photosynthesis. Ex- plants, trees.
  • Primary Consumers are herbivores animals, whose nutrition is directly based on plant products. Ex- Cow, deer, grasshoppers, small insects, etc.
  • Secondary consumers are carnivorous animals Like- small birds, wolfs, etc.
  • Tertiary Consumers are the top-level carnivore like men, lions, etc.
  • Only 10% of energy is transferred to higher levels from the previous one. So, the demand for food is more in higher levels.

Additional Information 

The correct answer is sulphur hexafluoride.Key Points

• Sulphur hexafluoride is a synthetic fluorinated gas with an extremely stable molecular structure, making it the most potent greenhouse gas ever found.
• It has a global warming potential of 23,500 times that of CO₂, meaning that it traps 23,500 times more heat in the atmosphere than CO₂.
• Sulphur hexafluoride is commonly used in electrical transmission and distribution equipment, as well as in the production of magnesium and aluminium.

Additional Information

• Hydrogen fluoride (option 1) is a highly corrosive gas used in the production of fluorine compounds, including sulphur hexafluoride.
• Sodium monofluorophosphate (option 2) is a salt commonly used in toothpaste to prevent tooth decay.
• Calcium fluoride (option 4) is a mineral found in teeth and bones and is also used in the production of aluminium.

The correct answer is Section 5 A.

Key Points

• The National Board for Wildlife (NBWL) -
  • It is constituted by the Central Government under Section 5 A of the Wildlife (Protection) Act, 1972 (WLPA). 
  • It may, at its discretion, constitute a Standing Committee under sub-section (1) of Section 5B.

Additional Information

• ​National Board for Wildlife (NBWL) -
  • It was formed in the year 2003 under the Wildlife (Protection) Act, of 1972.
  • It acts as the apex body in matters relating to forest ecology.
  • This body reviews matters relating to wildlife and construction or other projects around national parks and sanctuaries.
  • It is chaired by the Prime Minister.

The correct answer is 10%.Key Points

• The term "trophic level transfer efficiency" is the average amount of organic matter that is transferred from one trophic level to the next.
• This value is usually around 10%, meaning that only 10% of the organic matter from one level is transferred to the next level.
• Because energy is lost as metabolic heat when animals from one trophic level are consumed by species from the next, energy declines as it goes up the trophic levels.

Additional Information

• The food chain is a straight line made up of creatures in which energy and nutrients are passed from one to the next.
• When one creature eats another, this happens. 
• The decomposer organism comes at the end of the chain, having started with the producer organism. 

The correct answer is Low level ozone (or tropospheric ozone) is an atmospheric pollutant.

Key Points

• "Low-level ozone (or tropospheric ozone) is an atmospheric pollutant", this statement is true.
  • Tropospheric ozone is a short-lived climate pollutant with an atmospheric lifetime of hours to weeks.
  • It does not have any direct emissions sources, rather it is a secondary gas formed by the interaction of sunlight with hydrocarbons.
  • The conversion of Ozone to oxygen is an exothermic reaction.
  • It means when ozone gets converted into oxygen, heat is released.​

Additional Information

• Ozone (O3) is a triatomic molecule consisting of three oxygen atoms. 
• It is an oxygen allotrope.
• It has three electron groups around the central oxygen, and so has the trigonal planar electron geometry.
• It has one double bond and one single bond in its Lewis structure.

The correct answer is option 1 that is organic matter.

Concept:

• The concentration of hydrogen ions in the soil solution is measured by soil pH, which also serves as a gauge for the acidity or alkalinity of the soil.
• Some plants do best in neutral (pH 7) soil, while others do better in slightly acidic (pH 7) or slightly alkaline (pH > 7) soil.
• The ability of a plant to absorb nutrients can be hampered when the pH of the soil is too severe (either too acidic or too basic), which can have a detrimental effect on growth and productivity.
• Many minerals, including iron, manganese, and phosphorus, become less accessible for plant absorption in strongly alkaline or basic soils (pH significantly more than 7).

Explanation:

• The pH of the soil can be lowered (making it less alkaline) and overall soil health can be improved by adding organic matter, such as compost or well-rotted manure.
• These additives improve the activity of the soil's producing organic acid-producing organisms, which can aid in balancing the soil's alkalinity.
• Note that adding materials like quicklime or calamine solution would actually increase the soil's alkalinity, making it more basic rather than less. These choices would therefore not be suitable.
• It is typically advised that soil be tested to ascertain its current pH and nutrient levels before to making any modifications. This can assist in determining which adjustments, if any, would be most helpful.

Hence,the correct option is organic matter.

The correct answer is 10%.

Key Points

• About 10% of the energy available at one trophic level is transferred to the next level in an ecological pyramid.
• This principle is known as the 10% law, or the Lindeman rule.
• The remaining 90% of the energy is lost as heat due to the organisms' metabolic processes, such as respiration, movement, and maintaining body temperature.
• A breakdown of the energy flow in an ecological pyramid:
  • Producers (base of the pyramid): Capture energy from sunlight or inorganic chemicals (chemosynthesis) and convert it into organic matter (biomass) through photosynthesis or chemosynthesis.
  • Primary consumers (herbivores): Eat producers and transfer about 10% of the energy they consume to their own biomass.
  • Secondary consumers (carnivores): Eat primary consumers and transfer about 10% of the energy they consume to their own biomass.
  • Tertiary consumers (apex predators): Eat secondary consumers and transfer about 10% of the energy they consume to their own biomass.

Concept:

• An ecological pyramid is a pictorial representation of the relationship between different organisms in an ecosystem.
• It is of three types: Pyramid of the number, Pyramid of biomass, and Pyramid of energy.
• The base of each pyramid represents the producers or the first trophic level while the apex represents the tertiary or top-level consumer.

Explanation:

The Limitations of an ecological pyramid are:

• It does not take into account the same species belonging to two or more trophic levels.
• It assumes a simple food chain, something that almost never exists in nature; it does not accommodate a food web.
• The saprophytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.
• Thereby, the correct option is ''all of them''

Important Points

• The pyramid of biomass in the sea or pond is generally inverted because the biomass of fishes far exceeds that of phytoplankton.  

• The pyramid of energy is always upright, can never be inverted, because when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step.