Natural Resources and Environmental Science

CFCs (Chlorofluorocarbons) contain both Chlorine and Fluorine atoms bonded to Carbon. These compounds were widely used in refrigeration and aerosols before being phased out due to ozone damage.

Transpiration is the biological process by which water evaporates from stomata in plant leaves. This is different from perspiration (animals), condensation (gas to liquid), or respiration (energy production).

The ozone layer filters harmful UV radiation. Its depletion allows more UV-B and UV-C rays to reach Earth's surface, increasing skin cancer risk and ecosystem damage.

The Antarctic ozone hole was discovered in the 1980s and is most severe during Antarctic spring (September-October). Cold conditions and CFC accumulation create this seasonal phenomenon.

The greenhouse effect traps heat in Earth's atmosphere, maintaining average temperatures around 15°C instead of -18°C. Without it, Earth would be too cold for life as we know it.

Enhanced greenhouse effect from increased CO2, methane, and other gases traps more heat, raising global temperatures. This warming effect is the primary consequence of intensified greenhouse gases.

Condensation is the process where water vapor cools and transforms into liquid droplets, forming clouds. When these droplets grow heavy enough, they fall as rain.

Denitrifying bacteria convert nitrates and nitrites in soil back into nitrogen gas (N2), releasing it to the atmosphere. This completes the nitrogen cycle by returning nitrogen to its elemental form.

CO2 is a primary greenhouse gas that absorbs and re-emits infrared radiation. Unlike O2 and N2 which are transparent to infrared, CO2's molecular structure allows it to trap heat.

Animals obtain nitrogen primarily through consuming proteins (which contain nitrogen in amino acid structures). Plants synthesize proteins from soil nitrates, and animals acquire nitrogen by eating plants or other animals.

Evaporation is the process by which water changes from liquid to gas (water vapour). This occurs when water molecules gain enough energy from heat to escape into the atmosphere. Condensation is the opposite process (gas to liquid), while distillation is a separation technique and fragmentation is breaking apart solids.

Amino acids link together through peptide bonds to form proteins, making them the fundamental building blocks of all proteins. Fats are built from fatty acids and glycerol, vitamins are organic micronutrients, and sugars are carbohydrates - none of which are made from amino acids.

Denitrification is the microbial process that converts nitrates (NO3-) back into nitrogen gas (N2), returning it to the atmosphere. Nitrification converts ammonium to nitrates, putrification refers to protein decomposition, and ammonification converts organic nitrogen to ammonium.

Springs are natural outlets where underground water under pressure flows to the surface. Sewage refers to wastewater, rivers are surface water channels, and the sea is a large body of salt water - none of these represent underground water emerging naturally.

The ozone layer absorbs harmful ultraviolet (UV) radiation from the sun, protecting living organisms from DNA damage and skin cancer. It does not filter general air pollution or moderate solar heat - its primary function is blocking UV rays.

Greenhouses are enclosed structures that trap solar heat, maintaining warm temperatures for tropical plants during cold winters. Nurseries are for raising seedlings, gardens are outdoor planting areas, and orchards are for growing fruit trees - none provide the controlled warm environment that greenhouses do.

Earth's atmosphere contains approximately 21% oxygen, which is essential for most life forms and combustion. The remaining 78% is mostly nitrogen, with trace gases making up the final 1%. This 21% figure is a fundamental fact in atmospheric science.

Pulse plants (legumes like beans, lentils, peas) have root nodules containing nitrogen-fixing bacteria that convert atmospheric nitrogen into usable forms. Green, flowery, and non-green plants don't necessarily have this association - only legumes among pulses have this specialized nitrogen-fixing ability.

Photosynthesis is the primary biological process that produces oxygen as a byproduct when plants, algae, and cyanobacteria convert CO2 and water into glucose. Combustion consumes oxygen, hydrolysis breaks molecules using water, and ammonification produces ammonia - none release oxygen into the atmosphere.

Chlorofluorocarbons (CFCs) are synthetic compounds that break down in the stratosphere, releasing chlorine atoms that catalytically destroy ozone molecules. This led to the formation of the ozone hole. Oxides, sulphides, and hydroxides do not have this ozone-depleting effect.

When water percolates through soil and rock layers, it becomes groundwater or underground water. Surface water refers to water above ground like lakes and rivers, sea water is saline ocean water, and water vapours are gaseous water in the atmosphere.

CFCs release chlorine atoms when exposed to UV radiation in the stratosphere. These chlorine atoms react with ozone (O3), breaking it down into O2. One chlorine atom can destroy thousands of ozone molecules through a chain reaction.

Ozone has the chemical formula O3, meaning it consists of three oxygen atoms bonded together. It is an allotrope of oxygen, different from the O2 form we breathe.

Glass allows shortwave solar radiation to pass through but traps longwave infrared radiation, creating heat buildup. This is the same principle as the greenhouse effect where gases like CO2 trap heat in the atmosphere.

Lightning provides the enormous energy needed to break the strong triple bond in atmospheric nitrogen (N2). This allows nitrogen to react with oxygen, forming nitrogen oxides like NO and NO2.

Correct Answer: Nitrogen fixing in root nodule of legumes

Ozone has the chemical formula O3, which means it contains three oxygen atoms. It is a triatomic molecule and an allotrope of oxygen.

Graphite is a pure form of carbon in its elemental state. Salt contains sodium and chlorine, sugar contains carbon in compounds (not elemental), and rocks are primarily silicates.

Photosynthesis produces oxygen as a byproduct, it does not consume it. Combustion and respiration both use oxygen to produce energy, while oxide formation involves oxygen reacting with other elements.

Alkaloids are nitrogen-containing compounds found in plants, and urea (CO(NH2)2) contains nitrogen in its structure. Nitrogen is a key element in both of these organic compounds.

Ozone is indeed a poisonous/toxic gas that can cause respiratory damage. It is triatomic (O3), not mono-atomic. It is found in the stratosphere (upper atmosphere), not the lower atmosphere, and it absorbs UV radiation rather than reflecting it.

The ozone layer primarily absorbs ultraviolet (UV) radiation from the sun. This absorption protects living organisms from harmful UV rays that can cause skin damage and cancer.

Combustion of fossil fuels and biomass releases carbon dioxide into the atmosphere. Fossilization removes carbon from the cycle, while nitrification and ammonification are parts of the nitrogen cycle.

Photosynthesis uses carbon dioxide as a reactant to produce glucose and oxygen. Respiration does the opposite - it releases carbon dioxide as a waste product when breaking down glucose for energy.

Nitrites and nitrates are inorganic forms of nitrogen that plants absorb from soil and convert into organic compounds. Through nitrogen assimilation, these are reduced to ammonium and then incorporated into amino acids, which are the building blocks of proteins. This process is essential for plant growth and protein synthesis.

Oxygen is consumed during cellular respiration as the final electron acceptor in the electron transport chain, producing water and ATP. During photosynthesis, oxygen is released as a byproduct when water molecules are split to provide electrons for the light-dependent reactions. This reciprocal relationship sustains atmospheric oxygen levels.

Earth's atmosphere consists of approximately 78% nitrogen gas (N2), making it the most abundant atmospheric gas. This high percentage is crucial because nitrogen is essential for life, but most organisms cannot directly use atmospheric nitrogen in this form. The remaining atmosphere is primarily oxygen (21%), argon (0.9%), and trace gases including carbon dioxide (0.03%).

Cellular respiration is the metabolic process where cells break down glucose in the presence of oxygen to produce ATP, releasing carbon dioxide and water as waste products. This occurs through glycolysis, the Krebs cycle, and oxidative phosphorylation. Transpiration is water loss through leaves, decomposition is breakdown by decomposers, and fossilization is preservation of remains.

Photosynthesis is the process where plants, algae, and some bacteria use sunlight to convert atmospheric carbon dioxide (inorganic carbon) into glucose (organic carbon). This occurs through the Calvin cycle where CO2 is 'fixed' into carbohydrate molecules. Transpiration is water loss, fossilization forms fossils, and decomposition breaks down organic matter.