JKSSB Veterinary Pharmacist / Stock Assistant Study Material
Prepared by JKYouth.com Team.
| Topic | Marks |
| General Science | 20 Marks |
BASIC SCIENCE
- Sources of energy; Conventional & Non-Conventional
- Health, Hygiene and Sanitation
- Environmental pollution
- Nutrition, Respiration, Excretion etc
- Communicable & Non-Communicable Diseases.
- Ecosystem – Its components, Food chains and Food webs.
- Ozone layer, its depletion, Green House Effect.
- Importance of water in life
Sources of energy; Conventional & Non-Conventional
Energy is one of the major parts of the economic infrastructure, being the basic input needed to sustain economic growth. There exists a strong relationship between economic development and energy consumption.
The more developed is a country, the higher is the per capita of energy consumption and vice-versa. Human civilization relies on different sources of energy.
The two major sources of energy can be classified under:
- Conventional Sources
- Non-Conventional Sources
What are Conventional Sources of Energy?
These sources of energy are also known as non-renewable sources of energy and are available in limited quantity apart from hydro-electric power. Further, it can be classified under commercial and non-commercial energy.
Commercial Energy Sources
Coal, electricity and petroleum are known as commercial energy since the consumer needs to pay its price to buy them.
a) Coal
Coal is the most important source of energy. There are more than 148790 coal deposits in India. Between 2005-2006, the annual production went up to 343 million tons. India is the fourth-largest coal-producing country and the deposits are mostly found in Bihar, Orissa, Madhya Pradesh, Jharkand and Bengal.
b) Oil and Natural Gas:
Today oil is considered to be liquid gold and one of the crucial sources of energy in India and the world. Oil is mostly used in planes, automobiles, trains and ships. It is mainly found in Assam, Gujarat and Mumbai.
The total production of oil in India was 0.3 million tons in 1950-51, which increased up to 32.4 million tons in 2000-01.
c) Electricity:
Electricity is a common form of energy and used for domestic and commercial purposes. It is mainly utilized in electrical appliances like fridge, T.V, washing machine and air conditioning.
The major sources of power generation are mentioned below:
- Nuclear Power
- Thermal Power
- Hydro-electric power
1. Thermal Power:
Thermal power is generated at various power stations by means of oil and coal. It is a vital source of electric current and its share in the total capacity of the nation in 2004-05 was 70 percent.
2. Hydroelectric Power:
Hydroelectric power is produced by constructing dams above flowing rivers like Damodar Valley Project and Bhakra Nangal Project. The installed capacity of hydroelectric power was 587.4 mW in 1950-51 and went up to 19600 mW in 2004-05.
3. Nuclear Power:
The fuel used in nuclear power plants is Uranium, which costs less than coal. Nuclear power plants can be found in Kaiga (Karnataka), Kota (Rajasthan), Naroura (UP) and Kalapakam(Chennai).
Non-commercial energy sources
Generally, the energy sources that are freely available are considered non-commercial energy sources. The examples of non-commercial energy sources are straw, dried dung, firewood.
What are Non-Conventional Sources of Energy?
These non-conventional sources are also known as renewable sources of energy. Examples include solar energy, bioenergy, tidal energy and wind energy.
1. Solar Energy
This is the energy that is produced by sunlight. The photovoltaic cells are exposed to sunlight based on the form of electricity that needs to be produced. The energy is utilized for cooking and distillation of water.
2. Wind Energy
This kind of energy is generated by harnessing the power of wind and mostly used in operating water pumps for irrigation purposes. India stands as the second-largest country in the generation of wind power.
3. Tidal Energy
The energy that is generated by exploiting the tidal waves of the sea is known as tidal energy. This source is yet to be tapped due to the lack of cost-effective technology.
Difference Between Conventional and Non-conventional Sources of Energy
| Conventional sources of energy | Non-conventional sources of energy |
| These sources of energy are also known as a non-renewable source of energy | These sources of energy are also known as a renewable source of energy |
| They find both commercial and industrial purposes | They are mainly used for household purposes |
| These can be considered to be one of the reasons for the cause of pollution | These are not responsible for the cause of pollution |
| Coal, fossil fuels are two examples | Wind, solar energy and Biomass two examples |
Health, Hygiene and Sanitation
In medical terms, a complete state of physical, mental, social well-being and comfort can be combined to define health. Hygiene can be defined as a general practice followed in order to maintain good health. Based on maintenance, hygiene can be further classified into social hygiene and personal hygiene.
1. The World Health Day is celebrated on ________.
(a) 1st March
(b) 7th April
(c) 6th October
(d) 10th December
Sol: (b) 7th April.
2. Cleanliness, physical exercise, rest and sleep are a part of ________.
(a) Hygiene
(b) Social hygiene
(c) Personal hygiene
(d) None of the above
Sol: (c) Personal hygiene.
3. Which one of the following is an unhealthy habit?
(a) Sharing food
(b) Bathing twice a day
(c) Drinking boiled water
(d) Eating without washing one’s hand
Sol: (d) Eating without washing one’s hand.
4. Which one of the following is not a bacterial disease?
(a) AIDS
(b) Dengue
(c) Measles
(d) All of the above
Sol: (d) All of the above.
5. Which of the following diseases is also called as “Salmonella enterica serotype Typhi”?
(a) Typhoid
(b) Malaria
(c) Diarrhea
(d) Yellow fever
Sol: (a) Typhoid.
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6. Which of the following is the main cause for transmission of the Hepatitis virus?
(a) The bite of a mosquito
(b) Sharing drug needles
(c) Drinking contaminated water
(d) All of the above
Sol: (b) Sharing drug needles.
7. Which of the following statements is true about contamination?
(a) Contamination is caused by the entry of germs by an insect bite
(b) Contamination is caused by the entry of germs by an animal bite
(c) Contamination is caused by the entry of germs into drinking water or edible foods.
(d) None of the above
Sol: (c) Contamination is caused by the entry of germs into drinking water or edible foods.
8. Which of the following diseases is not caused by bacteria?
(a) Typhoid
(b) Poliomyelitis
(c) Tuberculosis
(d) All of the above.
Sol: (b) Poliomyelitis.
9. The main cause of contagious disease is _________.
(a) Contaminated Air
(b) Contaminated Food
(c) Poor hygienic conditions
(d) All of the above
Sol: (d) All of the above.
10. Which of the following factors is necessary for a healthy person?
(a) Vaccination
(b) Balanced diet
(c) Personal hygiene
(d) All of the above Sol: (d) All of the above.
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Environmental Pollution
Environmental pollution is defined as “the contamination of the physical and biological components of the earth/atmosphere system to such an extent that normal environmental processes are adversely affected.
Types of environmental pollution
- Air pollution – some of the most notable are sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, volatile organic compounds and airborne particles, with radioactive pollutants probably among the most destructive ones (specifically when produced by nuclear explosions)
- Water pollution – includes insecticides and herbicides, food processing waste, pollutants from livestock operations, volatile organic compounds, heavy metals, chemical waste and others
- Soil pollution (contamination) – hydrocarbons, solvents and heavy metals
In modern industrialized societies, fossil fuels (oil, gas, coal) transcended virtually all imaginable barriers and firmly established themselves in our everyday lives. Not only do we use fossil fuels for our obvious everyday needs (such as filling a car), as well as in the power-generating industry, they (specifically oil) are also present in such products as all sorts of plastics, solvents, detergents, asphalt, lubricating oils and in a wide range of chemicals for industrial use.
Among other pollution sources, agriculture (livestock farming) is worth mentioning as the largest generator of ammonia emissions resulting in air pollution. Of the total amount of greenhouse gasses, in agricultural production occurs about 30%. Thereof agricultural soil produce 32%, livestock 31%, crops cultivation 12%, from manure management occur 6% and 19% of other emissions.
Environmental pollution is causing a lot of distress not only to humans but also animals, driving many animal species to endangerment and even extinction. The trans boundary nature of environmental pollution makes it even more difficult to manage it.
It’s widely recognized that we are hugely overspending our current budget of natural resources – at the existing rates of its exploitation, there is no way for the environment to recover in good time and continue “performing” well in the future.
Everything on our planet is interconnected and while the nature supplies us with valuable environmental services without which we cannot exist, we all depend on each other’s actions and the way we treat natural resources.
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- 4. Human Excretory System
Human excretory system consists of:
- A pair of kidneys
- A pair of ureters
- A urinary bladder
- A urethra
- Kidneys are reddish brown bean shaped structure situated between last thoracic and lumber vertebra. Each kidney has a notch on its inner side called hilum through which ureter, blood vessels and nerves enter.
- Inside the hilum has broad funnel shaped space called renal pelvis with projection called calyces.
- Inside the kidney are two zone- outer cortex and inner medulla. Medulla is divided into medullary pyramids projecting into calyx.
- Cortex extends between medullary pyramids as renal column called Columns of Bertini.
- The functional unit of kidney is nephron. Each kidney contains about one million nephrons.
- Each nephron has two parts- the glomerulus and renal tubules. Glomerulus is the tuft of capillaries formed by afferent arteriole. Blood from glomerulus is carried away by efferent arteriole.
- Renal tubules starts with Bowman’s capsule continue with tubular parts divided into Proximal Convoluted tubules, Henle’s loop and Distal Convoluted tubule.
- The malpighian tubules, PCT and DCT of nephron are situated in cortical region where as loops of Henle’s into medulla.
| Juxta medullary Nephrons | Cortical Nephrons |
| a. Loop of Henle’s is short and extend only a little into medulla. | a. Loop of Henle’s are very long and extend deep into medulla. |
| b. The glomeruli lie close to the inner margin of the cortex. | b. The glomeruli lie in the outer cortex. |
Urine formation
- Glomerular capillaries blood pressure cause filtration of blood through 3 layers (endothelium of glomerular blood vessels, epithelium of Bowman’s capsule and basement layer between two membranes as ultra-filtration.
- The amount of filtrate formed by kidneys per minute is called glomerular filtration rate (GFR) which is 125 ml/minute.
- Glomerular Filtration rate is controlled by Juxta glomerular apparatus (JGA).
- 99% of filtrate has to be reabsorbed by renal tubules called reabsorption.
Function of Tubules
- Proximal Convoluted Tubules (PCT) – all the important nutrients, 70-80% electrolytes and water are reabsorbed.
- Henle’s Loop– maintains high osmolarity of medullary interstitial fluid.
- Distal Convoluted Tubules (DCT) – conditional reabsorption of Na+ and water. Maintains pH and sodium- potassium balance.
- Collecting Duct– large amount of water is reabsorbed to produce concentrated urine.
Mechanism of concentration of urine– The flow of filtrate in two limbs of Henle’s loop is in opposite direction to form counter current. The flow of blood in two limbs of vasa recta increase the osmolarity towards the inner medullary interstitium in the inner medulla.
- The transport of substance facilitated by special arrangement of Henle’s loop and vasa recta is called counter current mechanism.
Regulation of kidney function–
- Functioning of kidney is monitored by hormonal feedback mechanism of hypothalamus and JGA. Change in blood volume, body fluid and ion concentration activates the osmoreceptors in the body that stimulate the hypothalamus to release ADH or vasopressin hormones. The ADH facilitates water absorption in tubules.
- Decrease in glomerular blood pressure activate JG cells to release renin which converts angiotensinogen to angiotensin I and II that increase the glomerular blood pressure and release of aldosterone that increase absorption of Na+ ions and water.
Micturition – The process of expulsion of urine from the urinary bladder is called micturition. The neural mechanism that causes it is called micturition reflex. Urine formed in nephron is stored in urinary bladder till a voluntary signal is given by CNS. This initiates the contraction of smooth muscles of the bladder and simultaneous relaxation of the urethral sphincter causing the release of urine.
- Lungs, liver and skin also play important role in process of excretion. Lungs remove
and water, liver eliminates bile containing substances like bilirubin, biliverdin. Sweat glands remove NaCl, small amount of urea and lactic acid. Sebaceous glands excrete sterol, hydrocarbons and waxes.
Disorders of Excretory System
- Uremia– there is high concentration of non-protein nitrogen (urea, uric acid, creatinine). Urea can be removed by hemodialysis.
- Renal failure– also known as kidney failure where glomerular filtration is ceased and both kidney stops working. Kidney transplant is the ultimate method in correction of acute kidney failure.
- Renal Calculi– formation of stone or insoluble mass of crystallized salts formed within the kidney.
- Glomerulonephritis (Bright’s Disease)-inflammation of glomeruli of kidney due to entry of protein or red blood corpuscles in to filtrate due to injury.
- 5. Respiration
Respiration in all species is a metabolic process that occurs. It is a biochemical process inside the cells of organisms that takes place. Energy (ATP) is released in this phase by the breakdown of glucose, which is further used by cells to perform multiple roles. Breathing is carried out by every living animal, from a single-celled organism to a dominant multicellular organism.
| Respiration is characterised as the biochemical process in which the living cells of an organism generate energy, by taking in oxygen and releasing carbon dioxide from the oxidation of complex organic compounds. |
Respiration types
There are two types of respiration,
· Anaerobic respiration
It is a form of cellular respiration that occurs to generate energy in the absence of oxygen. For anaerobic respiration, the chemical equation is
| (C6H12O6) → 2(C2H5OH) + 2(CO2) + (ATP ) Glucose → Alcohol + Carbon dioxide + Energy |
· Aerobic respiration
It is a form of cellular respiration that takes place to generate energy in the presence of oxygen. It is a continuous process within the cells of animals and plants that occurs. With the assistance of the chemical equation, this phase can be explained,
| (C6H12O6) + (6O2) → (6CO2) + (6H2O) + (ATP) Glucose + Oxygen → Carbon dioxide + Water + Energy |
Phase of respiration
In prokaryotic cells, respiration occurs in the cytosol and across the plasma membrane. In eukaryotic cells, in the mitochondria, which is also known as the powerhouse of the cells, respiration takes place. The three respiration phases are,
Glycolysis
- The glucose molecules are converted into pyruvic acid, which is oxidised into water and carbon dioxide, leaving two carbon molecules known as acetyl-CoA.
- During the glycolysis process, two ATP and NADH molecules are formed.
- Pyruvate joins the inner mitochondrial matrix and, in the Kreb cycle, undergoes oxidation.
Oxidative Phosphorylation
- Oxidative phosphorylation is the mechanism in which a series of electron carriers produce ATP molecules as a consequence of the transfer of electrons from NADH or FADH2 to O2.
- Within the mitochondria of a cell, this process occurs.
Citric Acid Cycle
- It is often referred to as the cycle of tricarboxylic acid or Kreb’s cycle. In each step of the citric acid cycle, two ATP molecules are formed and occur within a cell’s mitochondrial matrix.
- In Kreb’s cycle, the electrons generated move across the mitochondrial matrix.
- Communicable and Non-communicable diseases
- Communicable diseases are those diseases, which can be transferred from one individual to another. Typically, it is caused by pathogens such as viruses, bacteria. For instance diseases such as AIDS, malaria, dengue etc. On the other hand, non-communicable diseases are the diseases which are not transmitted from one to another person. These are typically some of the allergies, nutrient deficiencies etc.
- Difference between Communicable and Non-communicable diseases
- The table below depicts the important differences between communicable and non-communicable diseases.
| Communicable Diseases | Non-communicable diseases | |
| Definition | ||
| Diseases spread from one to another person. Can be spread through water, air etc | Diseases cannot be transmitted from one to another person | |
| Causative | ||
| Pathogens that are highly infectious and vectors transmit these diseases | Here, the causative are allergies, malnutrition, illness due to internal factors, lifestyle changes, environmental changes, abnormalities in cell proliferation etc | |
| Agent causing infection | ||
| Virus, bacteria | No agents | |
| Inheritance factor | ||
| Cannot be inherited from one generation to another | Can be inherited from one generation to another | |
| Example | ||
| AIDS, Typhoid, Tuberculosis, Malaria, Cholera | Allergies, heart diseases, diabetes | |
| Type of disease | ||
| As it can develop almost immediately, it is acute | As it develops over a period of time and lasts for long, it is chronic | |
| Treatment | ||
| Traditional methods/therapies | Surgically or specialized methodologies |
- 6. Ecosystem – Its Components, Food chains and Food webs
Ecosystem Definition
An ecosystem is a system consisting of biotic and abiotic components that function together as a unit. The biotic components include all the living things whereas the abiotic components are the non-living things. Thus, an ecosystem science definition entails an ecological community consisting of different populations of organisms that live together in a particular habitat.
What is a food chain?
A food chain refers to the order of events in an ecosystem, where one living organism eats another organism, and later that organism is consumed by another larger organism. The flow of nutrients and energy from one organism to another at different trophic levels forms a food chain.
The food chain also explains the feeding pattern or relationship between living organisms. Trophic level refers to the sequential stages in a food chain, starting with producers at the bottom, followed by primary, secondary and tertiary consumers. Every level in a food chain is known as a trophic level.
The food chain consists of four major parts, namely:
- The Sun: The sun is the initial source of energy, which provides energy for everything on the planet.
- Producers: The producers in a food chain include all autotrophs such as phytoplankton, cyanobacteria, algae, green plants. This is the first stage in a food chain. The producers make up the first level of a food chain. The producers utilise the energy from the sun to make food. Producers are also known as autotrophs as they make their own food. Producers are any plant or other organisms that produce their own nutrients through photosynthesis. For example, green plants, phytoplankton and algae are some examples of producers in a food chain.
- Consumers: Consumers are all organisms that are dependent on plants or other organisms for food. This is the largest part of a food web, as it contains almost all living organisms. It includes herbivores which are animals that eat plants, carnivores which are animals that eat other animals, parasites are those organisms that live on other organisms by harming them and lastly the scavengers, which are animals that eat dead animals’ carcasses.
Here, herbivores are known as primary consumers and carnivores are secondary consumers. The second trophic level includes organisms that eat producers. Therefore, primary consumers or herbivores are organisms in the second trophic level.
- Decomposers: Decomposers are organisms that get energy from dead or waste organic material. This is the last stage in a food chain. Decomposers are an integral part of a food chain, as they convert organic waste materials into inorganic materials like nutrient-rich soil or land.
Decomposers complete a life cycle. They help in recycling the nutrients as they provide nutrients to soil or oceans, that can be utilised by autotrophs or producers. Thus, starting a whole new food chain.
Food Web:
Several interconnected food chains form a food web. A food web is similar to a food chain but the food web is comparatively larger than a food chain. Occasionally, a single organism is consumed by many predators or it consumes several other organisms. Due to this, many trophic levels get interconnected. The food chain fails to showcase the flow of energy in the right way. But, the food web is able to show the proper representation of energy flow, as it displays the interactions between different organisms.
When there are more cross interactions between different food chains, the food web gets more complex. This complexity in a food web leads to a more sustainable ecosystem.
Types of Food Chain
There are two types of food chains, namely detritus food chain and grazing food chain. Let’s look at them more closely:
- Detritus food chain: The detritus food chain includes different species of organisms and plants like algae, bacteria, fungi, protozoa, mites, insects, worms and so on. The detritus food chain begins with dead organic material. The food energy passes into decomposers and detritivores, which are further eaten by smaller organisms like carnivores. Carnivores, like maggots, become a meal for bigger carnivores like frogs, snakes and so on. Primary consumers like fungi, bacteria, protozoans, and so on are detritivores which feed on detritus.
- Grazing food chain: The grazing food chain is a type of food chain that starts with green plants, passes through herbivores and then to carnivores. In a grazing food chain, energy in the lowest trophic level is acquired from photosynthesis.
In this type of food chain, the first energy transfer is from plants to herbivores. This type of food chain depends on the flow of energy from autotrophs to herbivores. As autotrophs are the base for all ecosystems on Earth, the majority of ecosystems in the environment follow this kind of food chain.
Conclusion
Understanding food chains is vital, as they explain the intimate relationships in an ecosystem. A food chain shows us how every living organism is dependent on other organisms for survival. The food chain explains the path of energy flow inside an ecosystem.
Questions on Food Chain
What are the first organisms in a food chain?
Producers, also known as autotrophs, comprise the first level in a food chain.
What is the difference between the food chain and food web?
A food chain follows a single path, where animals discover food. But a food web shows different paths, where plants and animals are connected. A food web comprises several food chains.
In a food chain, an organism eats a single item, whereas in a food web an organism consumes multiple items. In a food chain, there is a singular path for energy flow and in a food web, there are different paths for energy flow.
What role do humans play in a food chain?
The role of humans in the food chain varies, depending on what the human consumes as food. If the human consumes only plants, they are known as primary consumers. If the human eats an organism that consumes plants, the human is known as a secondary consumer, and so on. So they are referred to as omnivores.
What are animals called in a food chain?
Animals are known as consumers in a food chain because they eat other plants and animals.
What do food chains end with?
A food chain begins with producers who make food, continues with consumers who eat the food and ends with the topmost predator.
Ozone Layer Definition
“The ozone layer is a region in the earth’s stratosphere that contains high concentrations of ozone and protects the earth from the harmful ultraviolet radiations of the sun.”
What is Ozone Layer?
The ozone layer is found in the lower portion of the earth’s atmosphere. It has the potential to absorb around 97-99% of the harmful ultraviolet radiations coming from the sun that can damage life on earth. If the ozone layer was absent, millions of people would develop skin diseases and may have weakened immune systems.
However, scientists have discovered a hole in the ozone layer over the Antarctica. This has focussed their concern on various environmental issues and steps to control them. The main reasons for the ozone hole are chlorofluorocarbons, carbon tetrachloride, methyl bromide and hydrochlorofluorocarbons.
Let us have a detailed look at the various causes and effects of ozone layer depletion.
Ozone Layer Depletion
“Ozone layer depletion is the gradual thinning of the earth’s ozone layer in the upper atmosphere caused due to the release of chemical compounds containing gaseous bromine or chlorine from industries or other human activities.”
What is Ozone Layer Depletion?
Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created.
Some compounds release chlorine and bromine on exposure to high ultraviolet light, which then contributes to the ozone layer depletion. Such compounds are known as Ozone Depleting Substances (ODS).
The ozone-depleting substances that contain chlorine include chlorofluorocarbon, carbon tetrachloride, hydrochlorofluorocarbons, and methyl chloroform. Whereas, the ozone-depleting substances that contain bromine are halons, methyl bromide, and hydro bromofluorocarbons.
Chlorofluorocarbons are the most abundant ozone-depleting substance. It is only when the chlorine atom reacts with some other molecule, it does not react with ozone.
Montreal Protocol was proposed in 1987 to stop the use, production and import of ozone-depleting substances and minimise their concentration in the atmosphere to protect the ozone layer of the earth.
Effects Of Ozone Layer Depletion
The depletion of the ozone layer has harmful effects on the environment. Let us see the major effects of ozone layer depletion on man and environment.
Effects on Human Health
The humans will be directly exposed to the harmful ultraviolet radiations of the sun due to the depletion of the ozone layer. This might result in serious health issues among humans, such as skin diseases, cancer, sunburns, cataract, quick ageing and weak immune system.
Effects on Animals
Direct exposure to ultraviolet radiations leads to skin and eye cancer in animals.
Effects on the Environment
Strong ultraviolet rays may lead to minimal growth, flowering and photosynthesis in plants. The forests also have to bear the harmful effects of the ultraviolet rays.
Green house effect
‘Greenhouse gases’ are crucial to keeping our planet at a suitable temperature for life. Without the natural greenhouse effect, the heat emitted by the Earth would simply pass outwards from the Earth’s surface into space and the Earth would have an average temperature of about -20°C.
Which gases cause the greenhouse effect?
The contribution that a greenhouse gas makes to the greenhouse effect depends on how much heat it absorbs, how much it re-radiates and how much of it is in the atmosphere.
In descending order, the gases that contribute most to the Earth’s greenhouse effect are:
- water vapour (H2O)
- carbon dioxide (CO2)
- nitrous oxide(N2O)
- methane (CH4)
- ozone (O3)
In terms of the amount of heat these gases can absorb and re-radiate (known as their global warming potential or GWP), CH4 is 23 times more effective and N2O is 296 times more effective than CO2. However, there is much more CO2 in the Earth’s atmosphere than there is CH4 or N2O.
Not all the greenhouse gas that we emit to the atmosphere remains there indefinitely. For example, the amount of CO2 in the atmosphere and the amount of CO2 dissolved in surface waters of the oceans stay in equilibrium, because the air and water mix well at the sea surface. When we add more CO2 to the atmosphere, a proportion of it dissolves into the oceans.
Importance of water in life
Water is one of the most important resources on the planet. Without water, life cannot exist. But what makes water so important? Water has several unique characteristics that make it an extremely valuable resource. Some such properties of water are listed below.
- Water is a very good solvent – it has the ability to dissolve many substances.
- The boiling point and freezing point of water make it easily available in all three states (solid, liquid, and gaseous).
- The specific heat of water is quite high. This enables water to absorb and release heat slowly, thereby regulating the temperature of its environment.
- Owing to its transparency, water can allow light to reach the life forms that are submerged in it. This is crucial for the survival of plant life in the oceans, lakes, and rivers.
- Water is neither acidic nor basic in nature. It has a pH of 7, making it a neutral substance.
These unique qualities of water, along with its abundance on the planet (approximately 71% of the Earth’s surface is made up of water), make it a crucial resource for plants, animals, and human beings.
Importance of Water in Living Organisms
- Water is the medium through which all essential vitamins and minerals are transported in the bodies of living organisms (owing to its ability to dissolve a wide range of substances).
- Water also plays a vital role in facilitating the work of enzymes in living organisms. For example, the sodium bicarbonate secreted by the pancreas is broken down into ions by water, making the medium sufficiently alkaline for the enzymes to work.
- Water helps maintain body temperatures in plants and animals. In order to decrease the temperature in their bodies, animals lose water via perspiration (sweating) and plants lose water via transpiration.
- Since water can rise in capillary tubes without any external help, it can be transported from the roots of trees to every other part of the tree.
- Water is an integral part of photosynthesis. Without it, autotrophic plants would not be able to produce their own food.
- Water serves as a habitat for more than 50% of all life on Earth.
Importance of Water in Human Beings
- Insufficient water content in the human body results in severe dehydration, which is often accompanied by kidney failure, seizures, and swelling in the brain.
- Water helps improve the circulation of oxygen throughout the body.
- It also plays a crucial role in the digestion of food.
- Water is a very important component of saliva, which helps break down food.
- The excretion of waste in the human body requires water. Insufficient water levels in the body may increase the strain on the kidneys, resulting in the formation of kidney stones.
Other Important Uses of Water
- If not for the high specific heat of water, the temperature of the Earth’s surface would be much lower. This would make it difficult for life to survive.
- The water in the Earth’s oceans absorb heat from the sun during the day and help maintain the temperature during the night.
- Water is necessary for the irrigation of crops and is, therefore, an integral part of agriculture.
- It is widely used in cooking activities since it boils at a temperature of 100o
- Humans make use of water for a wide range of domestic activities such as washing and cleaning.
- Water also serves as a medium for the transportation of cargo. Many goods are transported between the Earth’s continents via ships.
Industrial Uses of Water
- Many industries require large quantities of water for processing, cooling, and diluting products. Examples of industries that consume large quantities of water include the paper industry, the food industry, and the chemical industry.
- Water is also used as an industrial solvent for the production of several commercially important products. Almost all power plants that generate electricity employ water to spin turbines.
- Heavy water, an important form of water, is widely used in nuclear reactors as a neutron moderator.
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