Mix Example - NATURAL RESOURCES Questions in English

(B) Fossil fuels like coal and petroleum contain small amounts of nitrogen and sulphur.
When these fuels are burnt,they produce oxides of nitrogen and sulphur.
These gases cause respiratory problems and,in the presence of rain,form acid rain.
Furthermore,the burning of fossil fuels increases the concentration of suspended particulate matter in the air,which reduces visibility.

(N/A) Water pollution is caused by the addition of:
$(i)$ Undesirable substances like fertilizers,pesticides,or other poisonous chemicals.
$(ii)$ Sewage directly entering a water body.
$(iii)$ Hot water from power plants,which increases the water temperature and reduces dissolved oxygen,thereby killing aquatic organisms.
$(iv)$ Industrial effluents or radioactive substances discharged into water bodies.
We can contribute to reducing water pollution by taking the following measures:
$(i)$ Sewer lines should not be directly connected to water bodies.
$(ii)$ We should not dispose of garbage or domestic waste into water bodies.
$(iii)$ Prevent the dumping of toxic compounds into water bodies.
$(iv)$ Avoid washing clothes near water bodies,as detergents contain harmful chemicals.
$(v)$ Plant trees near river banks to prevent soil erosion,as erosion leads to the siltation of water bodies.

(N/A) Sunlight contains short-wavelength infrared radiation that can easily pass through the glass windows of the car. These radiations are absorbed by the interior surfaces,such as the seats and dashboard,which then re-emit the energy as long-wavelength infrared radiation (heat). Glass is opaque to these longer-wavelength radiations,preventing them from escaping the car. This phenomenon,known as the greenhouse effect,causes the trapped heat to significantly increase the temperature inside the vehicle.

(N/A) Dust particles remain suspended in the air and can cause various allergies and respiratory diseases in humans.
Dust affects plant growth by settling on the leaf surface and blocking the $stomata$, which interferes with photosynthesis and gaseous exchange.
Dust particles act as carriers for toxic substances, including heavy metals and harmful chemicals, which can be inhaled or deposited into the environment.

(N/A) The Sun heats the rocks during the day,causing them to expand. At night,these rocks cool down and contract. Because different components of the rock expand and contract at different rates,this uneven process leads to the development of cracks in the rocks. Over long periods,these cracks widen,causing the rocks to break into smaller particles,which eventually form soil.

(C) While $CO_2$ is essential for photosynthesis in plants,its concentration in the atmosphere is strictly regulated by natural cycles.
When human activities like burning fossil fuels and deforestation increase the concentration of $CO_2$ beyond natural levels,it acts as a pollutant.
High levels of $CO_2$ trap heat in the atmosphere,leading to the greenhouse effect and global warming,which causes climate change and rising sea levels.

(N/A) The primary factor responsible for the change in rainfall patterns in India is the prevailing wind patterns,specifically the monsoon winds. These winds carry moisture from the oceans to the land,and shifts in their direction and intensity significantly influence the distribution and timing of rainfall across the country.

(B) Soil erosion is the removal of the top layer of soil. In mountainous regions,the steep slopes and high-velocity water runoff make it extremely difficult to prevent or reverse soil erosion. Once the topsoil is washed away from these slopes,the underlying rock is exposed,making it nearly impossible for vegetation to regrow and for the soil to accumulate again.

(N/A) Regularly breathing in polluted air can lead to various respiratory and systemic health issues. Two common diseases caused by this are:
$1$. Asthma: Chronic inflammation of the airways.
$2$. Lung Cancer: Caused by the inhalation of carcinogenic particulate matter and toxic gases.
(Other examples include bronchitis,heart disease,or chronic obstructive pulmonary disease $(COPD)$).

(N/A) Two biologically important compounds containing nitrogen are:
$1$. Proteins: These are complex organic molecules made up of amino acids,which contain nitrogen in their amino group $(-NH_2)$.
$2$. Nucleic Acids ($DNA$ and $RNA$): These are the genetic materials of living organisms,and their nitrogenous bases (adenine,guanine,cytosine,thymine,and uracil) contain nitrogen.

(N/A) The two main causes for the increase in the concentration of $CO_{2}$ in the atmosphere are:
$(i)$ Deforestation: Trees and plants absorb $CO_{2}$ for photosynthesis. Large-scale cutting of forests reduces this absorption,leading to an increase in atmospheric $CO_{2}$ levels.
$(ii)$ Increased combustion of fossil fuels: The burning of fossil fuels like coal,petroleum,and natural gas for energy,transportation,and industrial activities releases large amounts of $CO_{2}$ into the atmosphere.

(N/A) Two factors that contribute to soil fertility are:
$1$. Humus: The presence of organic matter (decayed plant and animal remains) provides essential nutrients to the soil.
$2$. Microorganisms: Organisms like bacteria,fungi,and earthworms help in the decomposition of organic matter,which enriches the soil with nutrients and improves its structure.

(ROCKS) The major source of minerals in the soil is the weathering of rocks. Over millions of years,various physical,chemical,and biological processes break down large rocks into smaller particles,which eventually form the mineral component of the soil.

(B) The process of converting ammonia $(NH_3)$ into nitrites $(NO_2^-)$ and subsequently into nitrates $(NO_3^-)$ by soil bacteria is known as Nitrification.

(N/A) $CFCs$ stands for $Chlorofluorocarbons$. These are organic compounds that contain carbon,chlorine,and fluorine,produced as a volatile derivative of methane,ethane,and propane. They were commonly used as refrigerants,propellants in aerosol applications,and solvents. However,their use has been largely phased out due to their role in ozone layer depletion.

(N/A) The various components of soil include:
$1$. Small particles of rock (weathered rock materials).
$2$. Humus (decayed organic matter).
$3$. Living organisms (such as bacteria,fungi,earthworms,and insects).
$4$. Air and water trapped between the soil particles.

(C) Chlorofluorocarbons $(CFCs)$ released into the atmosphere reach the upper layers of the atmosphere (stratosphere).
In the stratosphere,these $CFCs$ react with ozone $(O_3)$ molecules,leading to their depletion.
This significant thinning of the ozone layer,particularly observed over Antarctica,is referred to as an ozone hole.

(B) The ozone layer is located in the stratosphere of the Earth's atmosphere.
It acts as a protective shield by absorbing the majority of the harmful ultraviolet $(UV)$ radiation emitted by the sun.
If these $UV$ rays were to reach the Earth's surface,they would cause severe damage to living organisms,including skin cancer,cataracts,and damage to the immune system in humans,as well as harm to crops and marine life.

(N/A) Two biologically important compounds that contain both nitrogen and oxygen are nitrates $(NO_3^-)$ and nitrites $(NO_2^-)$.
These compounds are essential components of the nitrogen cycle,where they are utilized by plants for protein synthesis and are crucial for soil fertility.

(N/A) Greenhouse gases are gases that trap heat in the atmosphere,contributing to the greenhouse effect.
Examples of greenhouse gases include $CO_2$ (Carbon dioxide),$CH_4$ (Methane),$H_2O$ (Water vapour),$N_2O$ (Nitrous oxide),and $O_3$ (Ozone).
Any two of these can be listed as the answer.

(A) Smog is a type of intense air pollution. The word comes from a combination of the words 'smoke' and 'fog'.
It occurs due to the presence of suspended particles like carbon particles or hydrocarbons in the atmosphere.
These particles cause visibility to be lowered,especially in cold weather,when water vapor also condenses out of the air onto these particles.

(N/A) Photosynthesis is the primary biological process by which green plants,algae,and cyanobacteria release $O_{2}$ into the atmosphere as a byproduct of converting light energy into chemical energy.

(N/A) The two organisms that play an important role in nitrogen fixation are:
$1$. $Rhizobium$ bacteria (found in the root nodules of leguminous plants).
$2$. Blue-green algae (such as $Anabaena$ and $Nostoc$).

(N/A) Decomposers are organisms that break down dead or decaying organic matter. Two common examples of decomposers are:
$1$. Bacteria
$2$. Fungi

(B) The mineral nutrients present in a particular soil are primarily determined by the parent rock from which the soil was formed through the process of weathering. The chemical composition of the parent rock dictates the types of minerals available in the soil.

(B) The movement of air,known as wind,is primarily caused by the uneven heating of the Earth's atmosphere by the Sun.
Different regions of the Earth receive varying amounts of solar radiation due to factors like latitude,surface type (land vs. water),and topography.
This creates temperature differences,which lead to pressure differences in the atmosphere.
Air naturally moves from regions of high pressure to regions of low pressure to balance these differences,resulting in the movement of air or wind.

(A) Biodegradable pollutants are substances that can be broken down or decomposed into simpler,harmless substances by the action of microorganisms like bacteria and fungi. Examples include organic waste,food scraps,and paper.

(B) Ozone $(O_3)$ is a highly reactive and toxic gas. If it were stable near the Earth's surface,it would be extremely harmful to the respiratory systems of humans,animals,and plants. Therefore,its instability at ground level is beneficial for life on Earth.

(N/A) The soil type is primarily determined by the following factors:
$1$. Size of the soil particles (e.g.,sand,silt,or clay).
$2$. Amount of humus present in the soil.
$3$. Type and quantity of microorganisms present in the soil.
$4$. Climate and weathering processes of the parent rock.

(N/A) The primary winds responsible for bringing rain to India are:
$(i)$ South-west monsoon: This is the main rainy season in India,which brings the majority of the annual rainfall.
$(ii)$ North-east monsoon: This brings rainfall to the south-eastern parts of India,particularly during the winter months.

(N/A) The compounds of nitrogen that cause air pollution are oxides of nitrogen,specifically $NO$ (nitric oxide) and $NO_2$ (nitrogen dioxide).
These compounds are primarily released into the atmosphere through the high-temperature combustion of fossil fuels in automobiles,power plants,and industrial processes.

(B) Step farming,also known as terrace farming,is common in hilly regions because it helps to reduce the velocity of flowing water.
By creating flat steps on steep slopes,the speed of runoff is decreased,which significantly reduces the washing away of topsoil.
Therefore,it is primarily done to prevent soil erosion and maintain soil fertility.

(A) Fossil fuels such as coal and petroleum contain small amounts of nitrogen and sulphur.
When these fossil fuels are burnt,nitrogen and sulphur are also oxidized,producing various oxides of nitrogen and sulphur.
When these oxides dissolve in rainwater,they form acids (such as nitric acid and sulphuric acid),which leads to the phenomenon known as acid rain.

(N/A) $(i)$ The cyclic flow of nutrients and energy between the biotic (living) and abiotic (non-living) components of the biosphere is known as the biogeochemical cycle.
$(ii)$ The gas incorporated into life forms through the process of photosynthesis is carbon dioxide $(CO_2)$.

(N/A) $(i)$ $CO_2$ is fixed by plants to prepare food through the process of photosynthesis.
$(ii)$ $CO_2$ acts as a greenhouse gas that traps heat in the atmosphere,which helps in maintaining the Earth's temperature suitable for life.

(N/A) $O_2$ gas: Essential for respiration in living organisms,supports combustion,and is involved in the formation of oxides of nitrogen.
$O_3$ gas: Acts as a protective shield in the stratosphere by absorbing harmful ultraviolet $(UV)$ radiations from the sun,which prevents them from reaching the Earth's surface and causing damage to living organisms.

(N/A) The two chemicals present in living organisms composed primarily of carbon,hydrogen,and oxygen are Carbohydrates and Fats.
$1$. Carbohydrates: They serve as the primary source of energy for the body,providing fuel for cellular activities.
$2$. Fats: They act as a concentrated source of energy and are essential for storing energy,insulating the body,and protecting vital organs.

(N/A) Wind is caused by the movement of air from one region to another due to the uneven heating of the Earth's atmosphere by the Sun.
$(b)$ Two methods of preventing soil erosion are:
$1.$ Afforestation (planting more trees).
$2.$ Terrace farming (or contour ploughing).

(A) The biosphere is a dynamic yet stable system due to the constant interaction between its biotic (living) and abiotic (non-living) components.
This interaction involves the continuous cycling of matter and the flow of energy through various trophic levels and ecosystems,which maintains the balance of the biosphere.

(N/A) The two forms of oxygen found in the atmosphere are:
$1$. $O_2$ (Diatomic Oxygen): It is essential for the process of respiration in living organisms and is also required for combustion (burning) of fuels.
$2$. $O_3$ (Ozone): It is found in the upper atmosphere (stratosphere) and acts as a protective shield by absorbing harmful ultraviolet $(UV)$ radiations from the Sun,preventing them from reaching the Earth's surface.

(N/A) Three processes in which oxygen is used are:
$1$. Respiration: Living organisms consume oxygen to break down glucose and release energy.
$2$. Combustion: Burning of fuels requires oxygen.
$3$. Formation of oxides: Oxygen reacts with various elements (like metals and non-metals) to form oxides.
The process by which oxygen returns to the atmosphere is:
$1$. Photosynthesis: Green plants release oxygen as a byproduct during the process of food synthesis.

(N/A) $(i)$ Plants primarily utilize nitrogen in the form of nitrates $(NO_3^-)$ and nitrites $(NO_2^-)$,which are absorbed from the soil through their roots.
$(ii)$ Nitrogen is an essential element for plants because it is a fundamental component of amino acids,which are the building blocks of proteins. Additionally,it is required for the synthesis of nucleic acids $(DNA$ and $RNA)$,chlorophyll,and various enzymes necessary for plant growth and development.

(B) $(i)$ Through the process of photosynthesis,green plants convert atmospheric $CO_2$ into glucose,thereby fixing carbon into organic compounds.
$(ii)$ Many marine organisms use carbonates dissolved in sea water to construct their shells and skeletons,effectively sequestering carbon from the environment.

(N/A) During the daytime,the land heats up faster than the water. The air above the land becomes hot and rises,creating a low-pressure area. Cooler air from the sea moves towards the land to fill this space,resulting in a $sea \ breeze$.
At night,the land cools down much faster than the sea. The air above the sea remains warmer than the air above the land. This warm air above the sea rises,and the cooler air from the land moves towards the sea to replace it,which is known as a $land \ breeze$.

(N/A) The greenhouse effect is the process by which certain gases in the Earth's atmosphere trap heat from the sun,preventing it from escaping back into space and thereby warming the planet.
$(b)$ The primary greenhouse gases responsible for this effect include Carbon dioxide $(CO_{2})$,Methane $(CH_{4})$,Nitrous oxide $(N_{2}O)$,and Chlorofluorocarbons $(CFCs)$.
$(c)$ The impact of the greenhouse effect on the global climate is known as global warming,which leads to the melting of polar ice caps,rising sea levels,and significant changes in weather patterns worldwide.

(N/A) Acid rain is caused by the presence of pollutants like sulphur dioxide $(SO_2)$ and nitrogen dioxide $(NO_2)$ in the atmosphere. These gases react with water vapor in the air to form sulphuric acid and nitric acid,which fall to the ground with rain.
Damage to living organisms:
$1$. In plants: It leads to stunted growth,yellowing of leaves (chlorosis),and can eventually cause the death of the plant.
$2$. In animals and humans: It causes skin irritation,itching,respiratory problems,and can lead to long-term health issues due to the accumulation of toxic metals leached from the soil.

(N/A) $1$. Biodegradable pollutants: These are substances that can be broken down into simpler,harmless substances by the action of natural biological agents such as bacteria and fungi. Examples include cow dung,vegetable peels,and paper.
$2$. Non-biodegradable pollutants: These are substances that cannot be decomposed or broken down by natural biological agents. They persist in the environment for a very long time and cause pollution. Examples include plastic,glass,and heavy metals.

(N/A) Nitrogen fixation is the process of converting atmospheric nitrogen $(N_2)$ into usable forms like ammonia $(NH_3)$ or oxides of nitrogen $(NO_x)$.
Plants require nitrogen to synthesize essential biological molecules such as proteins,nucleic acids ($DNA$ and $RNA$),and chlorophyll.
Although nitrogen is abundant in the atmosphere,plants cannot absorb it directly in its gaseous form $(N_2)$ because the triple covalent bond between nitrogen atoms is extremely stable and difficult to break. Therefore,they rely on nitrogen fixation to convert it into a form that can be assimilated by their roots.

(N/A) Water is found in all three states during the water cycle:
$(i)$ Gaseous state: Water exists as water vapour in the atmosphere.
$(ii)$ Liquid state: Water exists as liquid water in oceans,rivers,lakes,and as rain.
$(iii)$ Solid state: Water exists as ice and snow in polar regions and high altitudes.

(N/A) The two forms of oxygen found in the atmosphere are elemental oxygen $(O_2)$ and ozone $(O_3)$.
$(b)$ Biotic components include all living organisms such as plants,animals,and microorganisms. Abiotic components include non-living physical factors such as land (soil),air,water,sunlight,and temperature.