11th Part
Balanced Diet for Various Age Groups
Q. Mention the role of biotechnology in the field of agriculture.
A. Due to biotechnology certain favorable changes have been introduced in agriculture by scientists. Some of the examples of biotechnology are the high Yields seeds, resistance to diseases, improved nutritional quality, and adaptation to adverse environmental conditions. An important aspect in the production of improved plants is the breeding process. This enables one to combine, one or more, favorable quality of the parents to be passed on to their progeny. For this purpose, scientists use several methods for raising the plants. The most common methods are:-
(i) the traditional method, in which seeds and root stocks have been used as basic materials for raising plants,
(ii) the other method is the use of plant cells as any plant cell can give rise to a complete plant. These methods are useful not only for the improvement of present-day crops, but also for the creation of novel plants and new crops, which are of short duration, high-yielding-type, and resistant to diseases and other adverse environmental conditions.
Q. Mention the names of two diseases caused due to protein-calorie malnutrition. State their symptoms.
A. Two severe diseases which are caused due to the deficiency of proteins and protein-calorie are Kwashiorkor and Marasmus, respectively. Millions of children die annually and millions more go through a miserable life because of these diseases. They retard the child's physical growth and weaken its natural immunity to various infections. In extreme cases, children are mentally retarded and they never reach maturity and thus become a burden to the family and the nation.
Symptoms of Kwashiorkor - The symptoms of kwashiorkor include: change in the skin and hair colour (to a rust colour) and texture, fatigue, diarrhoea, loss of muscle mass. failure to grow or gain weight, edema (swelling) of the ankles, feet, and belly. It also leads to the damaged immune system, which can lead to more frequent and severe infections. Hence the child is exposed to diseases. Due to low energy food and protein intake, the child gradually loses the appetite and often develops weaning diarrhoea.
Symptoms of Marasmus - Thin face, Ribs, and shoulders clearly visible through the skin. Very loose skin that sometimes hangs in folds in the upper arms, thighs, and buttocks. Persistent dizziness, Sunken eyes, Diarrhoea, Active, alert, or irritable behaviour, and Frequent dehydration. This is manifested by severe retardation in growth, loss of muscles and subcutaneous fat.
Q. Why is soil considered a basic resource for agriculture? How can saline and alkaline soils be reclaimed?
A. Nature takes more than 50 years to build a centimeter of top soil. But every year, wind, water & human neglect, cause worldwide erosion of over 6,000 million tonnes of soil, along with 2.6 million tonnes each of nutrients like nitrogen and potassium, and 3.3 million tonnes of phosphorus. Though history has taught us that civilizations have vanished because of improper use of soil, still we are diverting millions of tonnes of excellent soil for brick-making and road laying. This wasteful practice should be drastically curtailed by making use of alternative and more durable materials for making bricks and roads. Today, our agricultural land is less than 0.33 hectares to a person, which is below the prescribed limit. It is time we created a country-wide awareness of the value of soil and the importance of scientific land use. We must understand that, if we neglect our soils, our future will be in peril.
Saline and alkaline soils are the result of centuries of neglect and mismanagement of our soils. About 7 million hectares of land is thus affected. These unproductive soils cover about 2.5 million hectares in arid Rajasthan and Gujarat, 1.4 million hectares in the black-soil region, and 2.1 million hectares in the coastal regions. Alkaline soils contain high amounts of carbonates and bicarbonates of sodium. Saline soils contain chlorides and sulphates of sodium, calcium, and magnesium. In both the above types of soils, salts are present in quantities large enough to interfere with crop growth.
It is now possible to reclaim alkaline soils with the cultivation of fodder grasses like Brachiaria mutica (Para ghas), Panicum antidotale (Neelon ghas) and Cynodon dactylon (Doob), and tree species like Prosopis chilensis (Vilayati khejri), Acacia nilotica (Kikar) and hybrid Eucalyprus. The trees establish quickly when planted in small holes filled with manure to which a little gypsum is added. In the very first year after reclamation with grasses, this soil can be used for planting other crops. Here, special varieties of rice can be grown as Kharif, and wheat as rabi crop.
The crucial factor in the management of saline soils is drainage. Saline soils have a high water-table. Drainage channels one meter deep and 30 meters apart effectively bring down the water table and help in reducing soil salinity. In the soils reclaimed in the above manner, sorghum, maize, and wheat which can tolerate salinity of soil can profitably be raised.
Q. What is Biotechnology? Describe the underlying techniques of genetic engineering and enzyme immobilization.
A. Biotechnology is a branch of science which deals with the use of biological systems, organisms to produce products on a large industrial scale. Due to biotechnology certain favorable changes have been introduced in agriculture by scientists. Some of the examples of biotechnology are the high Yields seeds, resistance to diseases, improved nutritional quality, and adaptation to adverse environmental conditions. An important aspect in the production of improved plants is the breeding process. This enables one to combine, one or more, favorable quality of the parents to be passed on to their progeny. For this purpose, scientists use several methods for raising the plants. The most common methods are:-
(i) the traditional method, in which seeds and root stocks have been used as basic materials for raising plants,
(ii) the other method is the use of plant cells as any favorable plant cell can give rise to a complete plant. These methods are useful not only for the improvement of present-day crops, but also for the creation of novel plants and new crops, which are of short duration, high-yielding-type, and resistant to diseases and other adverse environmental conditions.
Genetic Engineering - It involves the alteration of the genetic material of a particular plant, by the substitution or addition of new genetic material from some other plants. Presently, the scientists, are trying to transfer the genetic material, that enables legumes to fix nitrogen in the soil, to various economically important plants. If this is achieved, it would be a milestone in agriculture.
Tissue Culture - It makes use of the important quality of plant cells as any favorable plant cell can give rise to a complete plant. Based on this fact, any cell or a group of cells, or part of a plant such as a piece of stem, leaf, etc. can be grown on a nutrient medium under suitably controlled conditions in the laboratory. This method is commonly known as tissue culture. It enables us to get true-breeding types without going through the stages of flowering, production of seeds and their germination. This technique has great potential in our crop improvement programmes, and it has already been used in the improvement of varieties of wheat, rice, corn, and several other plants. This method is useful not only for the improvement of present-day crops, but also for the creation of novel plants and new crops, which are of short duration, high-yielding-type, and resistant to diseases and other adverse environmental conditions.
By applying the principles of biotechnology we can raise orchards where the fruit trees will be of desired, manageable height and form. The fruits will be of uniform size, shape, color and weight. They will have the same flavor and nutritional value and will ripen at the same time. This will make harvesting, storage, packing, transport, canning, and processing easy.
Q. Discuss the importance of nutrition for the health of a person. State the different nutrient groups with their respective functions.
A. To remain healthy and free of disease, our body requires certain kinds of food. The health of an individual is largely determined by the quality of food taken. Moreover, food makes a difference in our appearance, activity, behaviour, and in the quality of life. Foods vary in their composition and no one type of food contains all the required nutrients. A meal lacking in a particular requirement of our body for a prolonged period can result in disease, and even in death. Therefore, a knowledge of the food requirements of our body and various sources of obtaining them is essential. Studies carried out in many countries show that a good diet has promoted proper growth in children and has improved the general health of the people. Conversely, lack of diet, or diet without essential nutrients can lead to a steady decline in the physical and mental growth of these children and they suffer from various deficiency diseases. Scientists have determined the chemical substances present in different foods and their role in the body. They call these substances "nutrients" and have classified them in different groups. These are Carbohydrates, protein, minerals, fats, water, vitamins. Their functions are -
1. Carbohydrates and Fats are the main energy source for the body. Carbohydrates are easily available and are the cheapest source of energy. Fats also serve as an "emergency energy store" in the body, to be used, for example, when enough food is not available due to fasting or starvation. Therefore. carbohydrates and fats are called Energy Foods.
2. Proteins are the raw material used for building muscles, skin, blood, and bones. They repair the tissues which are constantly worn out. Therefore, we need to have proteins every day. Proteins can also serve as an energy source if the energy need of the body is not met by carbohydrates and fats. They also help us to fight infection.
Proteins are called Body Building Foods.
3. Minerals and Vitamins are not a source of energy but they are necessary in many of the steps involved in the release of energy in the cells. Thus, they help the body to make good use of food. They protect us from illness. Minerals, such as calcium, are the basic components of bones and teeth. Iron is a component of the red pigment of blood called haemoglobin. Minerals are important in the transmission of nerve impulses and for muscle contraction and relaxation. Vitamins and minerals are called Protective Foods.
4. Water is a component of all body fluids such as blood, digestive juices, etc. Water accounts for about 50 to 70% of the body's weight. It is essential for various metabolic activities. In fact, our body cannot utilize any substance, unless it is first turned into a form soluble in water. Digestion converts food into a soluble form so that it is readily absorbed and is carried by the blood to the sites where it is needed. The waste products like urea are carried by the blood to the kidneys from where they are excreted. Water also plays a role in regulating body temperature, through perspiration. The daily water requirement of the body depends on the climate, activity and the kind of food one takes.
Q. What is meant by a balanced diet? suggest the composition of a balanced diet needed by an adult working man.
Q. What is a balanced diet? Name four items in a meal which would make it a balanced meal.
A Balanced diet is a combination of various foods that fulfill all the basic requirements of the body in essential nutrients. The intake of a balanced diet can fulfill the energy needs of a person and can provide proteins, vitamins, minerals, carbohydrates and fats in proper quantity and proportion. It is required to keep him healthy, active and free from any disease.
Mixed cereals, Pulses, green leafy vegetables, and milk or milk products are the four important items that should be included in the meal to make it a balanced diet.
Q. (i) "Agriculture is the bedrock of the Indian economy." Justify the statement.
(ii) Write brief comments on the basic resources for agriculture in India.
A. Agriculture is the bedrock of the Indian economy as of the approximately 245 million working people in India, (1981 figures) 149 million people are engrossed in the agriculture sector. About 93 million were cultivators and 56 million were agricultural laborers. Together they constituted more than 60% of the total work-force of India. To these 149 million people, agriculture is not only the main source of income but a way of life. Almost 70%of the total population resides in villages which are completely dependent on agriculture-related activities. We have a total geographic area of about 329 million hectares. The net area under cultivation is 142 million hectares, of which about 31 million hectares are cultivated more than once a year, hence the total cropped area amounts to 173 million hectares. Our farmers and agricultural laborers, who constitute 60.5% of the work-force, contribute 34.7% of our total net national product. Hence, agriculture employs a large chunk of our manpower and provides the means to earn their Livelihood.
There are three basic resources for agriculture, they are sunlight, soil, and water.
Sunlight - It is the basic resource of agriculture which is used by plants for producing food during the photosynthesis process. During monsoon, the wettest season, the sky is overcast most of the time and thus the availability of sunlight is minimum. In summers, maximum sunlight is available, but unfortunately, it is the period when water availability is at its minimum. Winter, however, is the best period of the year, as there is enough of sunlight and moisture.
Soil
Soil is another important resource. Nature takes more than 50 years to build a centimeter of topsoil. Soil, which forms the uppermost layer of the land, is the most precious of all resources because it supports the whole life system on Earth. It provides food and fodder in the form of vegetation and stores water essential for life. It contains sand, silt, and clays, mixed with air and moisture. It possesses rich organic and mineral nutrients that are required for agriculture. The type of soil varies from place to place. Those soils which are rich in organic matter are fertile. Fertility is also dependent on the capacity of the soil to retain water and oxygen. There are different types of soils found in our country. Alluvial soils in the North Gangetic plains are the finest, black soils are next in productivity which are followed by red-and-yellow soils. The other kinds of soil available in our country are red soils, deltaic alluvial and Brown, laterite, desert, hill and mountain soils. Deep red soil is good for the cultivation of potatoes, bananas, pineapples, and rubber, etc. Black soil supports crops of sugarcane, groundnut, soybean, cotton, and rice, etc.
Water
Water is the third important resource in agriculture. A major problem in our country's agriculture is its dependence on rain to fulfill the requirements of water. Out of our net cultivated area of 142 million hectares, only 40 million hectares of area is covered by irrigation network. The rest is dependent on rain. In our country, which is situated in the monsoon belt of south-east Asia, the rainfall is neither uniform nor is evenly distributed throughout the year. As a result of it there are many regions in our country which get scanty rainfall resulting in agriculture failure.
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