IGNOU FST-01 Solved Assignments July 2010
Course Code: FST -01
Assignment Code: FST -01/TMA /2010-11
Maximum Marks: 100
Answer all questions.
Q1. a) Explain with the help of suitable examples that science in modern times is a collective and organized activity. (5)
Solution: The Scientific Revolution established science as a source for the growth of knowledge. During the 19th century, the practice of science became professionalized and institutionalized in ways that continued through the 20th century. As the role of scientific knowledge grew in society, it became incorporated with many aspects of the functioning of nation-states that science in modern times becomes so collective and organized activity.
The Collectivity of science is marked by a chain of advances in technology and knowledge that have always complemented each other. Technological innovations bring about new discoveries and are bred by other discoveries, which inspire new possibilities and approaches to longstanding science issues in modern Science for further organized activity.
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Q1.b) Describe the advances in the areas of chemistry, botany and zoology in India during Iron Age. (5)
Solution: The advances in the areas of chemistry in India during Iron Age:
The level of chemical knowledge and practices in the new ordered society is reflected in the pottery, iron tools and glass objects found at various Iron Age sites. The iron tools that you indicate a fairly advanced knowledge of iron smelting. By the fifth or the' fourth century B.C., the Indian metalworkers had attained a high degree of perfection in the techniques of producing iron and steel.
Glass objects unearthed in over 30 sites indicate that production of glass came to be known only towards the end of this period (Fig. 3.6). Ceramic bowls, dishes, lids and carinated jars ('handis') dated from about the sixth century B.C. to the second century B.C.. were also found in these sites. Fermentation methods, dyeing techniques, the preparation and use of a number of cheniicals and colour pigments were well known. Sketches of some ancient iron objects found at various sites Fig. 3.6: Sketches of some ancient glass such as Taxila, Hastinapur. Ujjain and Sisupalgarh: I) ringed chain; specimens from a) Taxila (6th century 2) lower portion of an iron axe: 3) miniature bell; 4) staple from a B.C.-1st century A.D.): I) ear-reel; 2) looped head: 5) spearhead; 6) slightly convex iron disc with seal; 3-5 beads; 6) bangle piece; 7) wine perforation; 7) spike of square section; 8) door ring; 9) circular flask (the thicker line was the piece that piece of iron with a nail rivetted into it; 10) fragment of a chain. was found); b) Arikamedu (1st century-2nd century A.D.): 8). 10) Roman glass bowls; 9) millefiori glass.
The advances in the areas of Botany in India during Iron Age:
In the Bronze and the Iron Ages, agriculture became the principal mode of production of man in all lands. It is, thus, not surprising that in India, botany and elementary plant physiology developed with the advances made in agriculture. The developments in medicine also helped these sciences. For example, in Rigvedic hymns, Atharvaveda, Taittiriya Samhita etc., scattered references are made to the following:
i) different parts of the plant such as mula (root), tula (shoot), kanda (stem), valsa (twigs) etc.
ii) classification of plants such as osadhi (medicinal), valli (climber), guccha (bushy) etc. according to their morphology and use, and
iii) physiology of plants in terms of what nourishes a plant through addition to the soil, suchas cowdung etc.
A systematic study of botany, 'Vrksayurveda' by Parasara, however, came into being byonly about the first century B.C. The treatise formalised a lot of the earlier botanical and medicinal knowledge. We will not go into its details.
The advances in the areas of Zoology in India during Iron Age:
The domestication of animals like horses and elephants and their use in warfare necessitated the study of their anatomy and physiology. A survey of Vedic literature has revealed that more than 260 animals were known at that time. Classification of animals and study of their dietary value had been attempted. Human physiology had also been studied. Post-Vedic literature also contains the names of animals and a vast storehouse of observations on their natural history. These observations may have stimulated the later thoughts and concepts about classification, heredity, embryology etc.
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2.a)Briefly discuss the impediments to the growth of science in medieval India. (5)
Solution: Impediments to the growth of science in medieval India in Mathematics:
The earliest traces of mathematical knowledge in the Indian subcontinent appear with the Indus Valley Civilization (c. 4th millennium BC ~ c. 3rd millennium BC). The people of this civilization made bricks whose dimensions were in the proportion 4:2:1, considered favorable for the stability of a brick structure.[25] They also tried to standardize measurement of length to a high degree of accuracy. They designed a ruler—the Mohenjo-daro ruler—whose unit of length (approximately 1.32 inches or 3.4 centimetres) was divided into ten equal parts. Bricks manufactured in ancient Mohenjo-daro often had dimensions that were integral multiples of this unit of length.
Indian astronomer and mathematician Aryabhata (476-550), in his Aryabhatiya (499) introduced a number of trigonometric functions (including sine, versine, cosine and inverse sine), trigonometric tables, and techniques and algorithms of algebra. In 628 AD, Brahmagupta suggested that gravity was a force of attraction.He also lucidly explained the use of zero as both a placeholder and a decimal digit, along with the Hindu-Arabic numeral system now used universally throughout the world. Arabic translations of the two astronomers' texts were soon available in the Islamic world, introducing what would become Arabic numerals to the Islamic World by the 9th century.During the 14th-16th centuries, the Kerala school of astronomy and mathematics made significant advances in astronomy and especially mathematics, including fields such as trigonometry and analysis. In particular, Madhava of Sangamagrama is considered the "founder of mathematical analysis".
Astronomy: The first textual mention of astronomical concepts comes from the Vedas, religious literature of India. According to Sarma (2008): "One finds in the Rigveda intelligent speculations about the genesis of the universe from nonexistence, the configuration of the universe, the spherical self-supporting earth, and the year of 360 days divided into 12 equal parts of 30 days each with a periodical intercalary month. The first 12 chapters of the Siddhanta Shiromani, written by Bhāskara in the 12th century, cover topics such as: mean longitudes of the planets; true longitudes of the planets; the three problems of diurnal rotation; syzygies; lunar eclipses; solar eclipses; latitudes of the planets; risings and settings; the moon's crescent; conjunctions of the planets with each other; conjunctions of the planets with the fixed stars; and the patas of the sun and moon. The 13 chapters of the second part cover the nature of the sphere, as well as significant astronomical and trigonometric calculations based on it.
Linguistics: Some of the earliest linguistic activities can be found in Iron Age India (1st. millennium BC) with the analysis of Sanskrit for the purpose of the correct recitation and interpretation of Vedic texts. The most notable grammarian of Sanskrit was Pāṇini (c. 520 – 460 BC), whose grammar formulates close to 4,000 rules which together form a compact generative grammar of Sanskrit. Inherent in his analytic approach are the concepts of the phoneme, the morpheme and the root.
Medicine: Findings from Neolithic graveyards in what is now Pakistan show evidence of proto-dentistry among an early farming culture.Ayurveda is a system of traditional medicine that originated in ancient India before 2500 BC, and is now practiced as a form of alternative medicine in other parts of the world. Its most famous text is the Suśrutasamhitā of Suśruta, which is notable for describing procedures on various forms of surgery, including rhinoplasty, the repair of torn ear lobes, perineal lithotomy, cataract surgery, and several other excisions and other surgical procedures.
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b) List the different operations that make up method of sciences. With the help of an example, explain these operations.(5)
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3. a) Draw a labelled diagram of electro-magnetic spectrum showing the wavelength of all the forms of electro-magnetic radiations. (5)
Solution: Draw it from your FST-01 Text Book.
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b) Describe the features of satellite moon gathered till date by the scientists. (5)
Solution: One of 18 different categories of lunar features recognized in the current system of IAU nomenclature. The IAU defines a satellite feature as "a feature that shares the name of an associated feature".
* On the Moon, this term is used exclusively in connection with what were formerly called "lettered craters" -- that is, craters which share the name of a "parent" feature (usually a crater) and are distinguished from it by the use of a letter, or very occasionally, two letters, as a suffix. For example, Plato A is a satellite feature of Plato.
* The parent crater is sometimes called the "patronymic" crater, but this is not an official term.
* Satellite features are not necessarily small. Indeed, as with human children, some lettered craters are larger and more prominent than their "parents".
* The list of non-crater parents is small. The following are the only non-crater features with satellite craters named after them
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4.a)Describe Miller’s experiment. How this experiment is supported the chemical evolution? (5)
Solution: Miller in 1952 created a closed system of laboratory glassware, except for tungsten electrodes that provided electric sparks, which mimicked lightening. He added together methane, ammonia, water, and hydrogen, subjected the mixture to a high-frequency spark for a week, and produced milligram quantities of glycine, alanine, and other amino acids. (6,7) Amino acids are building blocks that may hook together to form the long and complex molecules of animal and plant life. Miller lectured in 1961, “It appears likely that reactive organic compounds were formed by electric discharges and by ultraviolet light in the atmosphere of the primitive earth. These compounds were carried on by the rains and reacted in the ocean to give amino acids and other complex organic compounds. It is possible that a significant fraction of the carbon on the surface of the earth was in the form of organic compounds in the oceans. Reactions in this mixture would give a great many of the compounds that are components of present living organisms.
“While amino acids are easily synthesized in the laboratory, the synthesis reported here is the first one carried out under conditions that might reasonably be present on the primitive earth. The synthesis of amino acids is not the synthesis of life, nor is it a synthesis of proteins. However, it represents a step toward our understanding of how live matter may have arisen on earth.” (8)
Miller was not the first scientist to attempt to create an organic compound from inorganic molecules. In the 1820s, German physician-chemist Frederich Woeller (1800-1882) used ammonium cyanate to synthesize urea, a biological compound secreted by the kidneys. Woeller’s experiment was the first example of the reaction of inorganic compounds to form a biological compound. Today, the distinction between organic (of biological origin, e.g., urea, amino acids) and inorganic (of non-biological origin, e.g., carbon monoxide, graphite) is nebulous.
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b) Describe any two types of evidences that support the evolution of Homo sapiens. (5)
Solution: Homo sapiens, our own species, is distinct from other mammals: great apes such as chimpanzees, gorillas and orangutans and from early hominids. At some point between 8 and 4 million years ago gorillas and then chimpanzees split off from the evolutionary line that would lead to humans. As Michael H. Hart explains in his fine book Understanding Human History, Australopithecus afarensis, our likely hominid forefather, lived in East Africa about 3.5 million years ago. The Australian anthropologist Raymond Dart (1893-1988) discovered the first fossil of an Australopithecus africanus, a slightly more evolved version of A. afarensis, in 1924 in southern Africa. It was neither ape nor human and caused a stir at the time. Prior to this find, most Western scholars had believed that humans evolved in Eurasia.
Louis Leakey (1903-1972), the son of British missionaries, was an archaeologist and naturalist working in British-ruled East Africa. He went to school at Cambridge University in England, majoring in anthropology and graduating in 1926. From the very start Louis felt that our species arose in Africa, a concept which is now widely held but was controversial at that time. Through their tireless exploration and research, Louis and his English wife, the archaeologist and anthropologist Mary Leakey (1913-1996), made the Olduvai Gorge in the Serengeti region in northern Tanzania, famous for its wildlife, their domain. They made a series of spectacular paleoanthropological and archaeological discoveries in East Africa and founded a Leakey family dynasty of leading scientists that is currently in its third generation.
Lucy, the skeleton of an Australopithecus afarensis that lived 3.2 million years ago, was discovered in Ethiopia in 1974 by the American paleoanthropologist Donald Johanson (born 1943) along with the French anthropologist Yves Coppens (born 1934). The genus Homo diverged from Australopithecines more than two million years ago with Homo habilis, which made very crude stone tools called Oldowan after the Olduvai Gorge. About 1.8 million years ago a new species, Homo erectus, arose in East Africa, the first hominid to spread out of Africa. The earliest fossil of Homo erectus (“human that stands upright”), the Java Man, was discovered by Dutch physician and paleoanthropologist Eugène Dubois (1858-1940) in 1891 on the island of Java, then under Dutch colonial rule. H. erectus existed not just in Africa but in parts of Eurasia as far as Java in Southeast Asia, but apparently never settled in Australia or the Americas; this was achieved by early modern Homo sapiens during the past 40,000 years.
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5. a) With the help of a labeled diagram explain the energy flow through an ecosystem.(5)
Solution: Draw it from your FST-01 Text Book.
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b) Discuss the impact of increasing population on environment.(5)
Solution: The impact of increasing population on environment:
In the past decade in every environmental sector, conditions have either failed to improve, or they are worsening because of increasing population.
* Public health:
Unclean water, along with poor sanitation, kills over 12 million people each year, most in developing countries. Air pollution kills nearly 3 million more. Heavy metals and other contaminants also cause widespread health problems. Amount of land lost to farming by degradation equals 2/3 of North America.
Food supply:
Will there be enough food to go around? In 64 of 105 developing countries studied by the UN Food and Agriculture Organization, the population has been growing faster than food supplies. Population pressures have degraded some 2 billion hectares of arable land — an area the size of Canada and the U.S.
Freshwater:
The supply of freshwater is finite, but demand is soaring as population grows and use per capita rises. By 2025, when world population is projected to be 8 billion, 48 countries containing 3 billion people will face shortages.
Coastlines and oceans:
Half of all coastal ecosystems are pressured by high population densities and urban development. A tide of pollution is rising in the world’s seas. Ocean fisheries are being overexploited, and fish catches are down.The demand for forest products exceeds sustainable consumption by 25%.
* Forests:
Nearly half of the world’s original forest cover has been lost, and each year another 16 million hectares are cut, bulldozed, or burned. Forests provide over US$400 billion to the world economy annually and are vital to maintaining healthy ecosystems. Yet, current demand for forest products may exceed the limit of sustainable consumption by 25%. 2/3 of the world’s species are in decline.
Biodiversity:
The earth’s biological diversity is crucial to the continued vitality of agriculture and medicine — and perhaps even to life on earth itself. Yet human activities are pushing many thousands of plant and animal species into extinction. Two of every three species is estimated to be in decline.
Global climate change:
The earth’s surface is warming due to greenhouse gas emissions, largely from burning fossil fuels. If the global temperature rises as projected, sea levels would rise by several meters, causing widespread flooding. Global warming also could cause droughts and disrupt agriculture.
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6. a) With the help of suitable examples explain why renewable resources should be preferred over non-renewable resources. (5)
Non-renewable resources such coal, oil, fossil fuels....etc are not preferred. This is because once they have been used, they are not replaced in the nature. Instead the more they are used, the more they finish. Also, such resources have one big disadvantage; they cause air pollution when burned as they release toxic gases.
Renewable resources are preferred as they are the best ones. Once used, they do not decrease; they are replaced by nature itself. For example, solar energy, wind energy, tidal energy....etc.
These types of energy do not cause pollution and they are good for the environment.
In the years to come, the non-renewable resources will cease to exist but the renewable ones will still be there.
Taking into consideration all these advantages and disadvantages, we come to a conclusion that renewable resources are much better and that is why they are preferred over non-renewable resources
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b) Discuss the ways to use, plan and manage the land resource. (5)
Solution: Duty of care
All landholders have a statutory obligation of duty of care for the land, and must take all reasonable and practical steps to prevent harm to the environment and to areas of cultural heritage.
Incentives for sustainable management
The department provides advice on technical matters and policy direction related to a number of incentive schemes for sustainable land and water management administered by QRAA (formerly the Queensland Rural Adjustment Authority).
Property planning
Effective planning is the essence of good land management. Landholders can use property-level planning to document resources and management practices, and to design property changes. In some cases, preparation of such a plan is a regulatory requirement.
Land and water management plans
The purpose of land and water management plans (LWMPs) is to ensure that irrigation water-use practices are sustainable. In certain circumstances, the requirement for an LWMP can be triggered by the Water Act 2000.
Land degradation
Land degradation problems include salinity, soil erosion, soil acidification and soil compaction, which have arisen as a result of factors such as land management practices, drought, and urban development.
Statutory covenants
A statutory covenant is a written agreement that may be registered on title. The department has developed guidelines to help those who are preparing to enter into statutory covenants to protect land.
Land Manager's Monitoring Guide
The Land Manager's Monitoring Guide provides a suite of natural resource monitoring information to assist land managers in monitoring and demonstrating the results of more sustainable management actions.
Soil and land resources
Queensland soils and land resource information provides a description of landscapes and their characteristics and attributes for land management and planning.
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7. a)Giving examples, explain how are livestock a resources for us? (5)
Solution: Livestock farming is a sign of modern civilization. Countries that domestically raise livestock have a stable food source. Livestock production also creates many jobs from the farm to the processing to the grocery store or restaurant. Go to the meat section of your grocery store and see how many types of meat there are.
Problems are use of petroleum fuels by farmers, and possible environmental problems when farms get too big. Animals, including horses, mules, oxen, camels, llamas, alpacas, and dogs, are often used to help cultivate fields, harvest crops, wrangle other animals, and transport farm products to buyers. Animal husbandry not only refers to the breeding and raising of animals for meat or to harvest animal products (like milk, eggs, or wool) on a continual basis, but also to the breeding and care of species for work and companionship. Livestock production systems can be defined based on feed source, as grassland - based, mixed, and landless.
Grassland based livestock production relies upon plant material such as shrubland, rangeland, and pastures for feeding ruminant animals. Outside nutrient inputs may be used, however manure is returned directly to the grassland as a major nutrient source. This system is particularly important in areas where crop production is not feasible because of climate or soil, representing 30-40 million pastoralists.Mixed production systems use grassland, fodder crops and grain feed crops as feed for ruminant and monogastic (one stomach; mainly chickens and pigs) livestock. Manure is typically recycled in mixed systems as a fertilizer for crops. Approximately 68% of all agricultural land is permanent pastures used in the production of livestock.
Landless systems rely upon feed from outside the farm, representing the de-linking of crop and livestock production found more prevalently in OECD member countries. In the U.S., 70% of the grain grown is fed to animals on feedlots.[46] Synthetic fertilizers are more heavily relied upon for crop production and manure utilization becomes a challenge as well as a source for pollution.
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b) How can saline and alkaline soils be reclaimed? (5)
Solution: Alkaline soils are soils (mostly clay soils) with a high pH (> 9) and a poor soil structure and a low infiltration capacity. The are not saline, i.e. the total amount of soluble soils, especially sodium chlorides, is not excessive (ECe < 4 to 8 dS/m). Often they have a hard calcareous layer at 0.5 to 1 m. depth.
Causes
The causes of soil alkalinity are natural or they can be man-made. The natural development is due to the presence soil minerals producing sodium carbonate upon whethering. The man-made development is due to the application of irrigation water (surface or ground water) containg a relatively high proportion of sodium bicarbonates) The extent of alkaline soils is not precisely known. Important research on alkaline soils has mainly occurred in Central Europe and North India (above the Ganges river), where alkaline soils occur frequently.
Problems Alkaline soils are difficult to take into agricultural production. Rainwater stagnates on the soil easily and, in dry periods, irrigation is hardly possible. Agriculture is limited to crops tolerant to surface water logging (e.g. rice, grasses) and the productivity is low.
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8. a) Explain why vitamins are essential for us. (5)
Vitamins are essential for the normal growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a fetus begins to develop, at the moment of conception, from the nutrients it absorbs. It requires certain vitamins and minerals to be present at certain times. These nutrients facilitate the chemical reactions that produce among other things, skin, bone, and muscle. If there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage.
For the most part, vitamins are obtained with food, but a few are obtained by other means. For example, microorganisms in the intestine—commonly known as "gut flora"—produce vitamin K and biotin, while one form of vitamin D is synthesized in the skin with the help of the natural ultraviolet wavelength of sunlight. Humans can produce some vitamins from precursors they consume. Examples include vitamin A, produced from beta carotene, and niacin, from the amino acid tryptophan. Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs that make up a multicellular organism; they also enable a multicellular life form to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for respiration.
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b) How does our body fight with the invading germs? (5)
Solution: The immune system, which responds to an invading pathogen, is an intricate system of defense mechanisms designed to block and destroy any foreign substance entering the body. It is made up of many cells, which help it to perform its function. One of the major types of cells is white blood cells. White blood cells are responsible for the defense system in the body. There are approximately ½ a million white blood cells in every drop of human blood. White blood cells fight infections, and protect our body from foreign particles, which includes harmful germs, and bacteria. White blood cells, like red blood cells are formed from the stem cells of the bone marrow.Once the immune system fails to work properly, there is a disruption in the body’s ability to maintain homeostasis. This disruption will eventually cause diseases. The breakdown of the immune system in people with HIV/AIDS leaves them susceptible to all types of diseases since the immune system is no longer able to fight off foreign organisms.
Knowledge of the function of white blood cells, and the immune system has led to doctors successfully transplanting organs from one organism to another without rejection. After the transplant, drugs are administered to suppress the action of the white blood cells, thus preventing them from attacking the foreign organ.
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9.a)With the help of an example explain that hormones work in close coordination with our nervous system. (5)
Solution: The stress response hormones cause a number of biochemical and physiological changes which in the short term are vital and healthy but if the stressor is chronic then these stress hormones can start to undermine our health. Our stress response is designed to be triggered mainly in the short term.
In the long term these hormones cause blood clotting to increase and blood cholesterol levels to elevate increasing the risk of many diseases such as heart disease, stroke and angina. Stress hormones also weaken the immune system in the long term leaving us more vulnerable to infections. Increases in blood pressure are another long term effect of these stress hormones increasing the risk of stroke, heart attack and kidney disease. Chronically tensed muscles brought about by the stress response can lead to pain in the neck and back for example.
They all have to do with growth, and you can see an over-abundance or a lack would certainly affect growth. Two other important hormones are ADH (anti-diuretic) and oxytocin. The first is responsible for affecting blood pressure. The second is very important for muscle control in the uterus and milk production at birth. Any changes in the production of these hormones would affect your growth. You could have dwarfism or you could be really tall. Your urine production could be altered. This could well affect your blood pressure. You might be retaining fluids and get puffy ankles. Your kidneys could be excreting elements it should keep. Normally a lot of the toxins leave your body through your kidneys. So you need to have them functioning properly. The pituitary hormones responsibilities are very widespread indeed!
The hypothalamus is located in the lower part of the central of the brain, just above the pituitary gland. It is the primary link between the endocrine (hormones) system and the nervous system. This makes it a very important hormone. It activates and controls the part of the nervous system that in turn controls involuntary body functions, the hormonal system, regulating sleep and appetite and body temperature and others body processes. Remember that it isn’t the gland that does this work: it’s the hormone (messenger). This is done by producing chemicals that either stimulate or suppress hormone secretions from the pituitary. (It seems to regulate the regulator.) You can appreciate if this hormone is out of balance, the messages would be much distorted. For example, getting messages not to eat as much or to eat more, could result in unhealthy body weights. Or you would be sleeping too little or too much. Or you could get incorrect messages that your body temperature is too hot or too cold when in fact it is just comfortable.
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b)Discuss the role of communications in economic development of a society. (5)
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10. Write the applications of the following. (10)
a) Semiconductors
Solution: A semiconductor is a material that has an electrical conductivity due to flowing electrons (as opposed to ionic conductivity) which is intermediate in magnitude between that of a conductor and an insulator. This means roughly in the range 103 to 10−8 siemens per centimeter. Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices. Semiconductor devices include the various types of transistor, solar cells, many kinds of diodes including the light-emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Similarly, semiconductor solar photovoltaic panels directly convert light energy into electrical energy. In a metallic conductor, current is carried by the flow of electrons. In semiconductors, current is often schematized as being carried either by the flow of electrons or by the flow of positively charged "holes" in the electron structure of the material. Actually, however, in both cases only electron movements are involved.
Common semiconducting materials are crystalline solids but amorphous and liquid semiconductors are known. These include hydrogenated amorphous silicon and mixtures of arsenic, selenium and tellurium in a variety of proportions. Such compounds share with better known semiconductors intermediate conductivity and a rapid variation of conductivity with temperature, as well as occasional negative resistance. Such disordered materials lack the rigid crystalline structure of conventional semiconductors such as silicon and are generally used in thin film structures, which are less demanding for as concerns the electronic quality of the material and thus are relatively insensitive to impurities and radiation damage. Organic semiconductors, that is, organic materials with properties resembling conventional semiconductors, are also known.
b) Computers
Solution: A computer is a programmable machine that receives input, stores and manipulates data//information, and provides output in a useful format.
While a computer can, in theory, be made out of almost anything (see misconceptions section), and mechanical examples of computers have existed through much of recorded human history, the first electronic computers were developed in the mid-20th century (1940–1945). Originally, they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs).[1] Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space.[2] Simple computers are small enough to fit into mobile devices, and can be powered by a small battery. Personal computers in their various forms are icons of the Information Age and are what most people think of as "computers". However, the embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are the most numerous.
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c) Enzymes
Solution: Enzymes are proteins that catalyze (i.e., increase the rates of) chemical reactions.In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Almost all processes in a biological cell need enzymes to occur at significant rates. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell.
Like all catalysts, enzymes work by lowering the activation energy (Ea‡) for a reaction, thus dramatically increasing the rate of the reaction. Most enzyme reaction rates are millions of times faster than those of comparable un-catalyzed reactions. As with all catalysts, enzymes are not consumed by the reactions they catalyze, nor do they alter the equilibrium of these reactions. However, enzymes do differ from most other catalysts by being much more specific. Enzymes are known to catalyze about 4,000 biochemical reactions.[3] A few RNA molecules called ribozymes also catalyze reactions, with an important example being some parts of the ribosome.Synthetic molecules called artificial enzymes also display enzyme-like catalysis.
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d) Laser.
Solution: Light Amplification by Stimulated Emission of Radiation (LASER or laser) is a mechanism for emitting electromagnetic radiation, often visible light, via the process of stimulated emission. The emitted laser light is (usually) a spatially coherent, narrow low-divergence beam, that can be manipulated with lenses. In laser technology, "coherent light" denotes a light source that produces (emits) light of in-step waves of identical frequency, phase,[1] and polarization. The laser's beam of coherent light differentiates it from light sources that emit incoherent light beams, of random phase varying with time and position. Laser light is generally a narrow-wavelength electromagnetic spectrum monochromatic light; yet, there are lasers that emit a broad spectrum of light, or emit different wavelengths of light simultaneously.
