Morphology of Flowering plants

1. Name  the structure which protects the root tip.
2. Name the root system that develops from any part of the plant body other than the radicle.
3. Name the part of the plant which develops from the radicle in dicots.
4. Name 2 aquatic plants with photosynthetic roots.
5. Name two plant with fleshy adventitious roots.
6. The 4 o'clock plant and sweet potato (Ipomoea batatas) are similar in one aspect and dissimilar in another aspect with reference to the nature and modification of roots. Write their difference.
7. Name the roots which have indefinite shape.
8. What is the name given to the modified stem of Opuntia?
9. Name the phyllode with one internode.
10. What is the main function of tendrils?
11. Give an example of cladode.
12. Thorn of Bougainvillea and the tendril of Cucurbita are homologous organs. How?
13. Which plant parts has transformed into (a) tendril of pumpkin and (b) thorn of citrus?
14. What takes over the function of photosynthesis in Opuntia?
15. What kinds of stems are found in banana and Amorphophallus?

Answers:

1. Root cap
2. Adventitious root system
3. Tap or primary root system
4. Trapa and Tinospora
5. Dahilia and sweet potato
6. Both the plants have the tuberous roots but the roots in 4 O'clock plant are lobed and modified tap root while the roots of the sweet potato are modified adventitious roots and arise singly.
7. Tuberous roots
8. Phylloclade
9. Cladode
10. Tendrils help in climbing
11. Asparagus
12. Both develop from the axil of the leaf but perform different functions. The former gives protection while the latter helps in climbing.
13. Both are modifications of stem
14. The stem is modified into a thick, flattened leafy structure to carry out photosynthesis in Opuntia.
15. Banana stem is a rhizome and Amorphophallus stem is a corm.

What is Living ?

The word living cannot be defined but Living things have a variety of common characteristics. Such characteristics distinguish the living from the non-living. They are as follows:

1. Metabolism : The sum total of all the chemical reactions taking place in a living body is called metabolism. All living organisms are made up of small and large chemical compounds which carry out different functions. 
2. Ability to Response: All organisms have the ability to sense the conditions in their surroundings and respond to these stimuli. Such stimuli may be physical, chemical or biological.
3. Reproduction: Since all cells come from existing cells, they must have some way of reproducing, whether that involves asexual (no recombination of genetic material) or sexual (recombination of genetic material). Most living things use the chemical DNA (deoxyribonucleic acid) as the physical carrier of inheritance and the genetic information. Some organisms, such as retroviruses (of which HIV is a member), use RNA (ribonucleic acid) as the carrier. The variation that Darwin and Wallace recognized as the wellspring of evolution and adaptation, is greatly increased by sexual reproduction.
4. Growth: Even single-celled organisms grow. When first formed by cell division, they are small, and must grow and develop into mature cells. Multicellular organisms pass through a more complicated process of differentiation and organogenesis (because they have so many more cells to develop).
5. Organization. Living things exhibit a high level of organization, with multicellular organisms being subdivided into cells, and cells into organelles, and organelles into molecules, etc.
6. Homeostasis. Homeostasis is the maintenance of a constant (yet also dynamic) internal environment in terms of temperature, pH, water concentrations, etc. Much of our own metabolic energy goes toward keeping within our own homeostatic limits. If you run a high fever for long enough, the increased temperature will damage certain organs and impair your proper functioning. Swallowing of common household chemicals, many of which are outside the pH (acid/base) levels we can tolerate, will likewise negatively impact the human body's homeostatic regime. Muscular activity generates heat as a waste product. This heat is removed from our bodies by sweating. Some of this heat is used by warm-blooded animals, mammals and birds, to maintain their internal temperatures.
7. Adaptation. Living things are suited to their mode of existence. Charles Darwin began the recognition of the marvelous adaptations all life has that allow those organisms to exist in their environment
8. Energy acquisition and release. One view of life is that it is a struggle to acquire energy (from sunlight, inorganic chemicals, or another organism), and release it in the process of forming ATP (adenosine triphosphate).
9. Detection and response to stimuli (both internal and external).
10. Interactions. Living things interact with their environment as well as each other. Organisms obtain raw materials and energy from the environment or another organism. The various types of symbioses (organismal interactions with each other) are examples of this. 

Circulatory Pathways Among Vertebrates

All vertebrate possess a muscular heart. They show 3 types of Circulatory Pathways : Single circulation, Incomplete double circulation and Double circulation.

frogs'heart 

fish's heart

1. Single Circulation: Fishes show the single circulation pathway. Their hearts are 2-chambered with an atrium and a ventricle. The heart pumps out only deoxygenated blood to the gills for oxygenation. The oxygenated blood is supplied to all body parts and the deoxygenated blood from all the parts is returned to the heart.  
2. Incomplete Double Circulation: Amphibians and the  Reptiles excluding crocodiles show the incomplete double circulation. The is 3 chambered with 2 atria and a ventricle. The left atrium receives oxygenated blood while the right atrium receives deoxygenated blood. But in single ventricle the oxygenated blood and deoxygenated blood get mixed up and that is pumped to all parts of the body.                   3. Double Circulation: Aves and Mammals show the double circulation. The heart is 4 chambered with 2 atria and 2 ventricles. The oxygenated and deoxygenated blood are completely partitioned from each other. The left auricle receives oxygenated blood, that passes into the left ventricle which pumps  it to all parts of the body. The right atrium receives deoxygenated blood from all the parts of the body that passes into the right ventricle which pumps it to the lungs for oxygenation. 

Dr. Har Gobind Khorana

Khorana died of natural causes on November 9, 2011 in Concord, Massachusetts. He was 89. His wife died in 2001. Their daughter Emily Anne died in 1979. A widower, he was survived by his children Julia and Dave.

Har Gobind Khorana (January 9, 1922 – November 9, 2011) was an Indian-born American biochemist who shared the Nobel Prize in Physiology or Medicine in 1968 with Marshall W. Nirenberg and Robert W. Holley for research that helped to show how the nucleotides in nucleic acids, which carry the genetic code of the cell, control the cell's synthesis of proteins. He even devised a method to make several copies of DNA, which he termed “Repair Synthesis” that was later rediscovered by Kary Mullis and named as Polymerase Chain Reaction or PCR.

"Khorana was among the pioneers of the now-familiar series of three-nucleotide codons that signal to the cell which amino acids to use in building proteins - for example, uracil-cytosine-uracil, or UCU, codes for the amino acid serine, while CUC codes for leucine," said MIT News.

Look for Substitute

"Should Animal Dissection be Necessary in Classroom Practical?"

Animal dissection causes great suffering to the animal. The animal is treated merely as an object of study rather than a living thing. Firstly, we should have theoretical knowledge of the dissection through means such as television and computers with the guidance of a teacher. It is a better substitute for animal dissection.

{This thought was published in Science Reporter, April 2007 at page number 47 in the regular column titled Point Counterpoint}

It's Our Duty

"Do We Still Need Science Popularization Efforts in India Even After More Than 60 Years of Scientific Pursuit?"

It is said that nearly 50 percent of all the children are still deprived of access to even elementary education. In many cases the teaching methods and environment are so antiquated or poor that many children end up as mere dropouts. Today it is a knowledge-world and science and technology provide the means to fulfill the needs of globalization. Besides, our constitution declares that it shall be the duty of every citizen of India to develop the scientific temper and spirit of inquiry. In this context, we still need science popularization efforts.

{This thought was published in Science Reporter, August 2008 at Page No.-48 in the regular column titled Point Counterpoint }

The Importance Of Physical Fitness

Physical fitness is the part of true health. The true health is not the state of mere absence of diseases but a dynamic state of well-beings in terms of physical, mental and behavioural aspects of life. It is the pre-requisite to the success in life.

In every field of life the great men of the world possessed sound physical and mental fitness. If one searches for happiness, one will discover it coupled with the physical fitness. It is the best positive feature of humans. It is unique possession for the life. It is wealth. It makes life worth living. The importance of physical fitness cannot be described in words. Its necessity has become an inevitable feature of modern society.

It is all true. Humans are gifted with the faculty of reasoning and logical thinking. They are judicious creatures. Their dominance over other living things lies in their advanced brainpower. In fact, humans have been able to control Nature due to their highly developed intelligence or the brain. But, for the improvement of the mental power, it is indispensable that the body, too, should be hale and hearty.

‘A sound mind in a sound body’ is an oft quoted proverb. It emphasizes the importance of the physical fitness in our life. The mind can never be healthy, if the body is sick. The death of the body is the death of the mind; also. It is obvious that for intellectual development, the physical fitness is vital.

It is also important for the nation. Healthy and able-bodied citizens who bring athletic distinction to the nation at the international level are the priceless possession of a nation. In order to understand the importance of the physical fitness for a nation, the poignant words of the Father of the nation, Gandhi ji should be mentioned here. He said ‘India lives in the village and the strength of our nation depends upon the health of the rural folk, our richest heritage.’ Our country is not developed nation because of our effectiveness. Our effectiveness is very low in comparison to the effectiveness of the people of other country. When the effectiveness is low, the production cannot be increased and the prices cannot be lowered. So if we wish that the production of the country should be increased and consequently the goods should become cheaper, the fitness of the worker must be improved. Clearly, it has become the life-blood of the economy of a country. If we realize that the physical fitness is the noble wealth and maintain it, the whole earth will seem to be a paradise; otherwise the paradise will be lost.

The evolution of the living things and the creation of the variations are outcomes of the physical fitness. The theory of the survival of the fittest had its implication on the basis of physical fitness. The scientists know the value of physical fitness in the survival strategies of organisms ranging from smaller to the larger one. New diseases which are often a threat to us can be under the control only if we can develop the immunity against them. Undoubtedly, the physical fitness provides the power of resistance against diseases. This makes the need of physical fitness quite clear.

It is well known that our government is spending lakhs and lakhs of rupees for providing medical facilities. It is busy in fighting various diseases to make society free of them. But medical facilities alone can never solve this problem. It is also well known that diseases attack only those who lose their vitality and vigour. People with sound health may live even in poverty, but they never fail ill. So our people need physical exercises if they want to have disease free bodies.

Our body is thought to be made up of five elements: earth, water, fire, air and sky. Actually these are the things which are needed to survive in this world. We need the most fertile earth or soil for cultivation of the food grains and other objects of uses. We need clean water for drinking and performing other functions in which it is required. Similarly, fresh light, fresh air and open sky are also needed for our survival. Deficiency of any of those elements of life may cause our extinction. An ideal state of all above five elements is the state of the physical fitness.

For the students, its importance becomes many folds. Students have to do several mental works and to sit for long hours during studies. All these require energy and proper training for maintenance of good body postures. Otherwise, their posture becomes defective. They can neither sit nor stand properly. Their body begins to look very gauche. The backside does not remain upright but develops a curvature. Thus their spinal columns get ill-treated. So for our educational institutions, the management for physical exercise is very important. It is the only way; the students can maintain their health. For this very reason, other persons also, who carry on deskbound activities, must take some physical exercise each day.

Our forces need more and more young man with stout physical condition. Once our late Pandit Nehru said, “Every child of India shall have to be a soldier of freedom.” Only people with sound health who are sparkling over with heroism and patriotism can fight for their country’s sovereignty. It is only through physical fitness.

In our country the rate of infant mortality is quite high. The weak health of the parents is its main reason. Sick and diseased parents can reproduce only feeble and unhealthy offspring. The parents must be healthy, if they want to have healthy children. They must take some physical exercise daily.

Morning walk is good for health. It is the best form of exercise that keeps our body fit and active. It costs nothing yet it is very useful for our health. Those who live in towns and cities must take morning walk to get fresh air and energy. It makes us healthy and strong. It refreshes our mind. It strengthens our body. It saves us form many disease. It improves our digestion. We feel a good appetite after a long walk. It is equally good for the young and the old. It keeps us fresh for the whole day. It develops in us a good habit of rising early. It awakens in us love for nature. So it keeps us fresh healthy and energetic. Hence, it is of great advantages to us.

To be healthy we keep our houses clean. It should be well ventilated. It must get light from the sun. Our food plays an important part in the constitution of our health. It is a fuel for the body. In order to be healthy, food must be balanced. Besides these, body needs exercises. Regular exercise keeps us active. Rest after work is also necessary.

To be brief, for the individual as well as the social point of view physical fitness is very crucial. It is the constitutive ingredient of contentment. It makes our life fascinating, significant, intense and worth living. Even in paucity, one can enjoy peace and satisfaction much more than those of the rich. An exercise is the only way to maintain the physical fitness besides Yoga. Mental, emotional and physical development of the people can continue efficiently only if they take physical exercises. So, wherever possible, physical exercises must be made unavoidable.

Science: A Blessing Or A Curse

There is nothing good or bad but thinking makes it so......” -- Shakespeare

We are living in the scientific age that has undoubtedly proved a great boon to the human race. 

Science has given our control over nature. It is everywhere. Modern scientific discoveries have

 turned our lives into comfort and happiness. The uncivilized human beings became the civilized 

due to the advancement in the scientific knowledge. The post values have also undergone a sea 

change. Life has become far less difficult. In reality, science has revolutionized our life and soul. It 

has given us insight into almost everything that helps in improving life and enhances the quality of 

life-span. It is difficult to say how much we owe to science for the affairs of our life. Science has

 done wonderful job in the filed of agriculture. Better irrigation facilities, improved seeds, high-

yielding varieties, chemical fertilizers and scientific methods and practices of cultivation have 

increased the agricultural production many fold. Now, we are familiar with the nutritive value of food

 that we take in. Similarly, in the field of industry, it has proved its worth. Our material needs are

 fulfilled from the goods produced in the industry using several machines. It has furnished different

 ways of amusement. It has successfully created the tremendous entertainment value. Computer

 has done the creditable work to the perfection of our national well-being. Everything has been computerized today. Science has, indeed, facilitated the arduous tasks. We can do a greater 

volume of work in the shorter span and with less physical labour. The computing machines, the

ATMs and all such scientific gadgets have saved us from the drudgery of labour-intensive work. 

The modern man is, thus, enabled to live a full splendorous life. Science has created miracles in

 the domain of medical science. The invention of drugs or medicines has cured many incurable

 diseases which were formerly not amenable to treatment. With the help of X-rays, CT scanning machines and ultrasound, we can have our complete details of any ailments. Now, we can live a 

longer and healthier life due to science. Bubonic plague has been controlled. The small pox has

 been completely eradicated. Now, our efforts are in direction to the completely eradication of the

 polio disease. We cannot imagine the wonders of science.

Electricity has brought a great revolution in human life. Our radios, cinemas, televisions and other machines work on electricity. Electric fans, coolers and air conditioning plants, heaters etc are

 blessings of science which make us the master of our environment. Books, magazines and 

newspapers which are being published on a large scale have succeeded to eradicate ignorance

 among the people. It has conquered both the time and the distance. We have placed our foot on 

the moon. Now a day, we have the better means of communication and transport. It will not be an exaggeration to say that science has provided eyes to the blind, legs to the lame and hearing to

 the deaf. Side by side, we should not forget that if science is misused, it will prove fury to humanity.

 It has given us many things but we are misusing the scientific knowledge in various ways. Science 

has stimulated the process of industrialization that has resulted into the rise in competition, unemployment, pollution and capitalism. Atom and Hydrogen bombs are the weapons of the 

mass destruction. In itself, science is neither a curse nor a blessing. it is a great blessing

 provided that it should used in the welfare of mankind. Actually, Science is not to blame for 

colossal annihilation. It is the user who is to blame

Global Warming: Its Causes And Effects

Global warming is a potential environmental problem. It can be defined as a steady increase in the global mean temperature which may result in the imbalance of environmental conditions. We know that the vital source of energy in the cosmos is the sun. The sunlight consists of light of different wavelengths such as Ultraviolet rays, visible rays and Infrared rays. Among those different rays, the Infrared radiations are responsible for the heating effect of sunlight. Due to that heating effect, life is possible on the earth. The sunlight manages the optimum temperature in the earth’s atmosphere so that life processes and other physical and chemical activities may continue effectively. However, the entire sunlight is not reached to the earth. Actually, when sunlight reaches the earth’s atmosphere, it is either reflected or absorbed by the clouds, earth’s surface and atmospheric gases. Only 50% of incoming solar radiations or sunlight reach the earth and warm it up for survival of living organisms.

Air which is the mixture of various gases contains some gases such as carbon dioxide, CFCs, ozone, methane, water vapour and nitrous oxide that allow solar radiations to pass through them but they absorb as well as partially reflect back the infrared radiations. Those gases are called Green House Gases (GHGs). GHGs are responsible for keeping the earth warm because they can retain the heat of the sunlight within their molecules. When these molecules of gases absorb heat from sunlight beyond their limit, they emit the heating rays like a red hot piece of iron and increase the temperature of the surroundings. Recently, their concentration has started rising and has resulted in increasing the mean global temperature. This increase in the temperature is termed as the global warming. During the past century, the temperature of the earth has increased by 0.6 °C. It is estimated that the average global temperature may increase by 1.4-5.8 °C by the year 2100. The gradual increase in the temperature of the environment can damage the entire living systems operating on the earth. Clearly, it is the GHGs which are chiefly responsible for the global warming. Hence, it would be better to check the increasing concentration of GHGs in order to sustain life and life processes on the earth.

There are several natural and man-made factors which are responsible for the global warming. Volcanic eruptions and forest fire are some of the important natural causes. But anthropogenic activities like deforestation, rapid urbanisation and industrialisation are more accountable for its intensification to a great extent. At present human population is budding rapidly. It has resulted in increased consumption of fossil fuels like coal and house hold fuels like firewood etc. We are now witnessing the faster technological changes and revolution in agriculture and transport sectors. No doubt, all over the world developments are taking places at the cost of environment. All these, along with several other human activities have been giving out substantial quantity of GHGs and the world is being left for facing the challenges of global warming.

Although one of the important GHGs i.e. Carbon dioxide gas is a comparatively insignificant non-pollutant gas in the atmosphere, its higher concentration is of grim environmental apprehension. As it is the most common GHG, its elimination or alteration is of prime importance. Nature has a mechanism for conversion of carbon dioxide gas into oxygen. Plants play the role of natural transducers here. They utilize carbon dioxides during the process of photosynthesis to make their own food and release oxygen gases as by-products. In this way, they keep up the delicate balance of carbon dioxide in ecosystems. But, deforestation due to the human needs results in the irregular rainfall, frequent floods, soil erosion, ground water reduction and increased drought condition. It also reduces the very utilization of carbon dioxide and augments its amount in the earth’s atmosphere. The more carbon dioxide means the more absorption of sunlight and the more chance of causing global warming.

Unfortunately, several anthropogenic activities are not eco-friendly and they pave the ways for consequences of global warming. Rise in global temperatures causes many climatic changes but most drastic change will be the increase in sea-level. A rise in sea levels is possible because of melting of ice from the poles due to the global warming. Melting even a fraction of the volume of polar ice can result in flooding of many low lying areas around the earth. The rise in global temperatures has already resulted in cracks in the Antarctic ice shelf.

Global warming is, therefore, of great concern and should be taken seriously. Every sphere of life is significantly affected from it. On the one hand, it has shifted the pattern of crop-yields and biodiversity at various levels around the world. On the other hand, it has badly damaged the quality and quantity of freshwater. It also causes natural disasters and climatic changes including storms, hurricanes, earthquakes, floods, droughts and exceptionally warm summers. The summer of 1998 predicted to be the warmest in the century.

The International Panel on Climate Changes (IPCC) predicts a shift in the current agricultural production pattern away from the current production areas to the northern latitudes. Changes in ground water availability, increased occurrence of climate extremes and crop diseases are also predicated. Europe and America have already witnessed these changes considerably. If this process of global warming persists, the continued existence of different floras and fauna including humans will be very distressing. The impact of the global warming process will be felt several sectors such as agriculture, fisheries, forestry and industries etc. This would ultimately affect the economies of any country. The damages caused due to the global warming are equivalent to that of nuclear wars as both have massive irreversible outcomes.

According to the report submitted to the United Nations Environmental Programme (UNEP) in February 2007, greenhouse gases are responsible for cold days, hotter nights, killer heat waves, floods and devastation and droughts. Global warming can alter some of the vital activities of living organisms such as metabolism, behaviours, reproduction and embryonic development. It will eventually lead to the death. Health experts expect a rise in climate related diseases such as heat strokes and spreading of vector borne diseases such as malaria into areas so far unaffected. Others have warned about the outcomes of increased water shortages and increasing pollution.

Global warming forms warm air and it will result in the cooling of upper atmosphere. Ultimately, It will disrupt radio-communications and further warm the troposphere. In other words, it will have effects on the range of species, food production, damage to property, ecosystems loss, primary sector damages, low output in agriculture, defects in fishery and forestry, quality and quantity of water, different means of transports, tourism industries, pollutions, migration of organisms and risk of disasters. It will not be exaggeration to say that Global warming is a real problem and this is the right time to act against.

Man and Environment

Man and environment are interdependent and interrelated. Environment means the conditions that have an effect on the behavior and development of somebody or something. It has two fundamental components i.e. the physical component and the biological component. The physical part of environment comprise of light, temperature, humidity, wind, rainfall, land, water and air or atmospheric gases. Actually it includes the non-living physio-chemical factors of environment. The other component of environment is biological factors which include plants, animals and micro-organisms. In other words, the environment is considered as the physical and biological conditions in which all things exist. It is the basis of survival. It directs the continued existence, growth, development and reproduction of the humans.

Humans and their environment can be considered as a closed system since a cyclic exchange of materials such as Oxygen, Carbon, Nitrogen, Minerals and water between them takes place. In fact, everything that we use is obtained from the environment. We are delimited by our environment from which we derive our requirements. It will not be an exaggeration to say that man obliges environment for his endurance as it supplies energy and resources for him. We depend on it for crucial requisites and hence, we interact with different components or factors of the environment. It affects the distribution, structure, behavior and inter-relationship of man. All basic needs are directly derived from the environment.Water that constitutes the part of physical elements of environment is essential for life. Not only humans but other organisms also have to face different problems of water insufficiency or objectionable loads as floods. A proper regulation of water cycle is required for the proper functioning of life. Soil that provides water, minerals and fossil fuels to man is also another important part of the environment. No doubt, we have been affecting the environment from the very beginning as nomads to the present day civilized forms. The environment satisfies human wants. Are water, air, sunshine, land, soil, forests, wildlife, fishes, minerals and power resources etc. not useful to us? The environment is our sacred and priceless legacy.

With the development of human civilization environment has been dominated by humans. We face several environmental problems today because we ignore our environment for our greed and needs. As soon as we get up in the morning, we start to consume our various environmental resources and add pollutants to it. Our daily activities such as bathing, washing, cooking food, using automobiles etc. gradually harm our environment. It is also true that we cannot stop utilizing those resources but it should also be kept in mind that we care for cleanness and protection of our environment. The limited use of resources is not harmful or worthless. It is the time to think on it. The environment is capable of purifying itself to a certain extent. But the pressure has increase on it. Many anthropogenic activities including urbanization, industrialization and development activities have adverse effects on it. The smoke from vehicles and factories has degraded the quality of air. We, all, are facing the environmental pollutions. We cut down mercilessly several trees which resulted in the loss of biodiversity. Now the rainfall is not regular. Some regions are facing the problem of droughts and some other of floods. The excess use of chemical fertilizers altered the composition, quality and water holding capacity of soil. The protection and conservation of the environment is related to our own protection. It is the moral duty of all humans to take care of the health of our environment. We must manage to retain the purity of air, water and fertility of soil. We must encourage the environmental protection and conservation plans.

Each component of environment is essential whether it is living or non-living. Knowledge regarding the importance of environment should be made the part of school text books. A constant interaction between man and his environment goes on to produce more from the latter and to conserve it longer. Environment is not only complex and dynamic but also mutually reactive. It is not only environment but man also is in danger. Forests check pollution to a great extent. According to Ashoka the king’s duty is not to protect only citizens of the country and to punish the wrong doers. A king’s duty is also to preserve human animal life and forest tree. It was only Ashoka who had ordered that animals should not be killed for food and sports. What does it indicate? We should grow up with a sense of kinship with nature. Biotic components and abiotic factors are components essential for our development.

The seriousness of the problem of environmental degradation is evident from the fact that the Indian constitution has placed the protection of the environment in the class of fundamental duties of the citizens. June 5 of every year is celebrated throughout the world as Environment Day to make people think and act to protect and develop the environment. As our own very existence depends on it, we should keep the environment pure, clean and safe. We should set up many environment clubs, seminars and symposiums with a view to protecting and developing human environment. Clearly, our problems are anthropogenic; therefore, they can be solved by man. Man’s reason and spirit have often solved the seemingly unsolvable problems, and we believe they can do it again. We should not forget that the environment is older than man from the angle of their origin and growth. Man is the last species evolved on the earth. However both grow in close association with each other. It is right that man exists because the environment exists. The struggle of man as regards his existence and survival has been very formidable and the man has to fight tooth and nail in order to come out victorious. The environment has ever supported the man in this respect. But at times there is conflict between both of them. Thus for man environment is the supreme factor to influence his survival. Hence, the two cannot be estranged.

Dr. Homi Jehangir Bhabha

Dr. Homi Jehangir Bhabha was one of the greatest scientists that India has ever produced. He was a very good artist and musician, also. He is considered as the Father of Indian Nuclear Science. He is also known as the Father of Indian Electronics industry. He established Bhabha Atomic Research Centre. ‘Coming events cast their shadow before’ is a common saying. The early life of this great personality fully illustrates this proverb. He was born on 3rd October 1909 in an affluent Parsi family. He had been brilliant and meticulous person since his childhood. His father Mr. J H Bhabha was a renowned barrister at the Bombay High Court. Bhabhajee received his early education in Cathedral School. He then studied in Allonsion College and the Royal Institute of Sciences in Bombay. After that, he went to England for higher studies. He was only 17 then. He pursued his M Sc degree from the Cambridge University in 1931. He was a topper student there. He received many scholarships. His research was in higher Mathematics and Physics. He productively obtained his Ph D degree in 1934 at the Cambridge University. His research was related to the cosmic rays. He enunciated the Cascade Theory of Showers which was an amalgamation of two other theories i.e. the Pair Production Theory and Radiative Collision Theory. This theory was very noteworthy in the scientific world. A nuclear physicist, he theoretically explained the ways of finding the probability of the electron-positron scattering in atoms. He was chosen a fellow of the Royal Society of London in 1931.

He returned to India in 1941 and was signed up as a Reader at the Indian Institute of Science, Bangalore. He pioneered research work on nuclear Physics in India. He conducted many successful experiments at the Raman Institute. His uncle was Sir Dorabji Tata. With the help of his uncle, he founded the Tata Institute of Fundamental Research. He became its chairman.

When India got her independence in 1947, he who played a prominent role in developing the country’s nuclear energy programme became the first chairman of the Indian Atomic Energy Commission. He was also the president of the first United Nations Conference on ‘Peaceful Uses of Atomic Energy’. On 12th January 1957, the Atomic Research Centre was established at Trombay near Bombay. With the help of Canadian government three nuclear reactors were set up at that centre. He was also the chairman of Indian Science Congress in 1957. He was the first director of TIFR.

He has remarkable achievements to his credit. He received a number of awards in India as well as abroad. He got Adams awards (1937), Hopkins’s award (1948) and the Padma Bhushan (1954). He departed this life on 1966. It was a great loss not only in scientific world but also for India. His life was a real embodiment of the Indian principal of simple living and high thinking.

Air Pollution

The World Health Organization defines air pollution or atmospheric pollution as the presence of materials in the air in such concentration which are harmful to man and his environment. Air pollution is one of the most hazardous and common class of environmental pollution. It has an unfavorable effect on all living things. It brings about untimely fatality for flora and fauna. In recent years, the problem of air pollution has become very severe. It rises due to the hunger for riches and ignorance of human. A sign of development seems to be the increasing number of vehicles on Indian roads. But, the key cause of air pollution in the urban India is automobiles which inefficiently burn petroleum and release 80% of air pollutants. On the other hand, deforestation is on an unprecedented scale which has created a greater pressure on the quality of air. The large scale production by industrialization has also resulted in air pollution. Concentration of industries in one area is another major cause of it. One should remember that air pollutants even in small concentration are extremely destructive to life and assets. The combustion of fossil fuels like natural gas, petroleum and coal as well as wood in industries or automobiles or aircrafts or railways or thermal power plants, agricultural burning and domestic uses etc has caused the air pollution. Metallurgical processing creates mineral dust and fumes containing poisonous or toxic substances like fluorides, sulphides, lead, chromium, nickel, beryllium, arsenic, vanadium, cadmium, zinc, mercury etc. As a result, generations to come are likely to suffer from a number of incurable diseases. Its very extreme can even threaten the existence of human races. Chemical industries like asbestos, cosmetics, welding etc, cotton and textiles industry, wheat flour mills, stone crushing and gem grinding industry add to air pollution. It is estimated that 52% of air pollution is caused by carbon dioxide, 18% by sulphur dioxide, 12% by hydrocarbons and 10% by particulates consisting of soot, fly ash, dusts of various types, fur, hair, spores and pollen grains etc, 6% by nitrogen dioxides and 2% by the remaining. Some natural things and process may also cause air pollution to some extent. The natural air pollutants include pollens, spores, marsh gases, volcanic gases and synthesis of harmful chemicals by electric storms, lightning and solar flares.

Generally, air pollutants not only impair oxygen transport that results in giddiness, asphyxia, decreased vision and cardiovascular malfunction but also cause the damages of building, sculptures and painted surfaces etc. A study conducted by the World Bank in 1995 revealed that 40,000 Indians die prematurely due to the polluted air in cities. Yet another study made by the Environmental Protection Agency shows that every year nearly 40,000 children in India are affected by respiratory disorders caused by the growth of carbon dioxide in the atmosphere. Modern environmental biologists feel that the increase in air pollution may cause the reduction in the amount of sunlight energy reaching to the earth’s surface which lowers solar radiation at the earth’s surface and produce a cooling effect on world climates. It could ultimately prompt another ice age. The other scientists believe that the air pollution causes what is called the Green House Effect. It results in the heating of the earth’s surface. It is fueling global warming which has serious consequence for life on this planet. Recently certain ecologists have tried to correlate air pollution with serious and prolonged droughts, heavier rains and floods and more serious hurricanes and tornadoes. The reported threat to the Taj Mahal of Agra from nearby refinery of Maharastra is due to the presence of sulfur dioxides in air. If the air continues to be polluted in this way in urban India, humans will face greater and greater health hazards. Air will not remain breathable and health will suffer.

Chronic diseases like bronchitis, lung cancer and emphysema are caused by air pollution. It is estimated that mortality from lung cancer could be lowered 25% by a 50% reduction in air pollution. Due to air pollution the incidence of respiratory disease in Delhi is about 12 times the national average. Air pollutants also cause a number of other diseases including eye irritation, dizziness, headaches, nasal irritation, coughing and shortness of breath, sore throat, chest pains, increased cold and allergies etc. They also produce offensive odors and give general discomfort anxiety or suffering to people. There are several abiotic and biotic factors that can affect the response of plants to an air pollutant exposure dose. It causes soiling of clothing and curtains.

As air pollution is not visible to the naked eye, it cannot be handled or removed by individual efforts. It requires awareness among all the people to check the air pollution. At first, there should be balanced and planned industrializations in India. Urbanization should be well planned. Pollutants should be destroyed by the use of suitable scientific technique like incineration. A comprehensive programme of tree plantation should be taken in hand. Deforestation should be prohibited. Besides, an intensive research is essential to solve it. Certain other protective measures should also be adopted for effective control of this menace. There should be sustained efforts to find alternatives like solar powered vehicles and appliances to reduce our dependence upon oil engines to run vehicles and generator sets.

To measure and control the magnitude of air pollution in various industrial hubs of India, National Environmental Engineering Research Institute (NEERI) has set Air Monitoring Stations in Mumbai, Kolkata, Delhi, Madras, Hyderabad, Kanpur, Jaipur, Ahmedabad and Nagpur. Delhi is getting special attention on account of its high pollution level. The WHO has classified this city among the ten most polluted cities in the worked. In India, air pollution control legislation envisages the formation of Air Pollution Boards at the central and state levels with powers to issue and revoke licenses to polluting industries, enforce emission standards and frame rules and regulations for the control of air pollution. However, there is a need of legislation to deal with fumes of Petrochemical Units, ash, carbon particles and unpalatable smell and even noises from industrial units. In order to collect information about the nature, sources and extent of air pollution, a national Air Quality Monitoring Programme is conducted by the Central Pollution Control Board (CPCB) with the objectives of identification of areas in need of restoration of air quality and their prioritization, identification of nature and extent of pollution control need and assessment of the effectiveness of pollution control programme.. As vehicular emissions are major pollutants of ambient air quality, vehicular pollution is sought to be controlled.

Government of India’s new auto fuel Policy has laid out a road map to cut down vehicular pollution in urban India. The goal of this policy is to reduce sulphur and aromatics contents in petrol and diesel to 50ppm and 35% respectively. The Bharat stage II (equivalent to Euro II norms) will be applicable to all the automobiles throughout the country from April 1, 2005. Cities like Delhi, Mumbai, Chennai, Bangalore, Hyderabad, Ahmedabad, Pune, Surat and Kanpur. Agra will have to meet EuroII emission norms from April 1, 2005 and Euro IV emission norm from April 1 2020.

Air pollution may be controlled and reduced if industrial plants should be advised to use high chimneys for escape of smokes fumes or heated air. If the pollutants are part of the fuel, we can consider using fuels with lower pollutant content, removing the pollutant from the fuel and during the combustion process. The use of Compressed Natural Gas (CNG) has reduced air pollution to a great extent because CNG burns more efficiently than petrol or diesel. It is cheaper as well as very little of it is left unburnt. It, also, cannot be siphoned off by thieves or adulterated like petrol or diesel. Public awareness regarding air pollution, potential of sewage and many other solid wastes will certainly help in reducing air pollution in town and cities. It should be made mandatory for municipalities to carry out the proper treatment of sewage and other wastes. Many plant species have been evaluated for their scavenging potential against air pollutants. It has been suggested that the efforts should be made for green belt development since it serves as a sink for air pollutants. To remove the particulate matter in the air, it should be filtered before releasing it into the air. Plantation should be done on a large scale. Trees use carbon dioxide and release oxygen and depollute the air. Control equipments likes gravity settling tanks or porous filters and electrostatic precipitators should be installed in factories to minimize the air pollution

Human Male Reproductive System

Human male reproductive system consists of the following main organs:

1. Primary Sex Organs
2. Secondary Sex Organs
3. External Genitalia

1. Primary Sex Organ: The organs which produce sex cells or gametes and sex hormones are called Primary Sex Organs. Testes is the PSO of Human male. It is 2 in number. The testes are located outside the abdominal cavity within a pouch called Scrotum. This position is called extra-abdominal position. Scrotum provides a temperatures 2-2.5 degree C lower than the body temperature. It is due to the fact that formation of sperms (=spermatogenesis) requires low temperature.  

structure of Testis

Each testis is oval in shape. It measures about 5 cm in length, 2-3 cm width and about 3 cm in thickness. The  testis is covered by a dense covering called tunica albuginea. Internally the testis is divided into about 250 compartments called testicular lobules. Each lobule contains 1-3 highly coiled seminiferous tubules. Seminiferous  tubules are the structural and functional units of testis. Sperms are produced in the testis. The seminiferous tubule is internally lined bu germinal epithelium. The germinal epithelium consists of 2 types of cell : Sertoli cell and Male germ cell (Spermatogonia). Sertoli cells provide nutrition and shape to the developing germ cells and spermatozoa. The spermatogonia undergo cell divisions to form spermatozoa. The spaces between two seminiferous tubules have Leydig cells or Interstitial cells which synthesize and secrete the male sex hormones called androgens or Testosterone. 

2. Secondary Sex Organs: The organs which conduct gametes and sex hormones are called SSO. Duct system and Accessory glands are SSO. 

Duct System: The seminiferous tubules connect and form network called rete testis. From the rete testis arise 10-20 fine tubes called vasa efferentia. They open into the epididmis. The epididmis is a single convoluted tubule that is located along the posterior surface of the testis. The epididmis continues as the vas deferens or sperm duct. It loop over the urinary bladder and receives a duct from the seminal vesicle to form ejaculatory duct that runs through the prostate glands. The urethra receives the ducts of prostate gland and the Bulbourethral (Cowper's) gland and runs through the penis to its external opening called urethral meatus. 

Accessory glands: The accessory glands of male reproductive system include a pair of seminal vesicles, a prostate gland and a pair of Cowper's gland. Their secretions are collectively called as seminal plasma. Seminal plasma is rich in fructose, calcium and certain enzymes. It provides nutrition and a medium for the spermatozoa to swim in the female reproductive tract. The seminal plasma along with the spermatozoa is called semen. 

3. External Genitalia : Penis is the external genitalia in human males. It is made of special erectile  tissue that helps in erection of the penis to facilitate insemination. The enlarged tips of the penis is called glans penis. It is covered by a loose fold of skin  called fore skin or perpuce.