Science Que-Ans (Each of 3 Mark )

There are many types of health problems that can possibly arise after disaster such as victims of disaster might suffer from lack of nourishment due to inadequate food. The immediate health problems after disaster includes suffering of trapped people, people may suffer from fractures, burns and asthma due to dust particles arising from buildings. Contaminated water can also cause other health issues.

Malaria: Malaria is caused by a protozoan parasite Plasmodium. This disease spreads through the bite of an insect vector–the female Anopheles mosquito which feeds on human blood. Male Anopheles mosquito feeds upon plant juice. Main symptoms of malaria include headache, nausea, muscular pain and high fever. Malarial attack consists of three stages:

1. Cold stage, feeling of extreme cold and shivers.
2. Hot stage, high fever, faster respiration and heart beat.
3. Sweating stage, due to profuse sweating, temperature of the body goes down to normal.

Antibiotics are effective against bacteria but not against viruses. Antibiotics block specific pathways found in bacteria. Viruses do not have their own metabolic pathways, therefore, in order to reproduce us to use the metabolic pathways of the cells they infect.

Stagnant water (of pools, ponds) in the locality is the habitat of larvae of many types of mosquitoes and they are the vector of a disease, called malaria. Doctor confirms malaria if the patients have following symptoms: Headache, nausea, muscular pain and high fever. Doctor also checks the presence of malarial parasite in the human body by blood test.

Because these all are public transport so it might happen that an i'll person may sit on the seat so infection/ virus may be left on the seat when the i'll person touchs the seat and when you touch the seat the infection comes on you and you have to suffer.

Immunization: It is the development of resistance against a pathogen. It is carried out through vaccination. Principle of vaccination. Vaccination introduces a harmless antigen of a pathogen into the body. Our immune system develops some antibodies and memory lymphocytes against the pathogen. When the actual pathogen happens to enter the body, the immune system recognises its antigen through memory cells. The memory cells induce large scale synthesis of cytotoxic and antibody producing lymphocytes to eliminate the pathogen.

Good hygiene the primary way to prevent infections:

• Wash your hands well.
• Cover a cough.
• Wash and bandage all cuts.
• Do not pick at healing wounds or blemishes, or squeeze pimples.
• Don't share dishes, glasses, or eating utensils.
• Avoid direct contact with napkins, tissues, handkerchiefs, or similar items used by others.

A communicable disease is one that is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; breathing in an airborne virus; or by being bitten by an insect.If you caught that disease from another person or animal, it is called a communicable disease. These illnesses are usually caused by viruses or bacteria and are passed through the air, through contact with contaminated surfaces, or through contact with bodily fluids. Examples include colds, the flu, or HIV.

The difference between acute and chronic when used for diseases is that acute means extremely severe pain, brief and dangerous disease whereas chronic refers to a medical condition that lasts over a long period. Chronic also means something always present and recurring or something habitual.

Antibiotics: They block biochemical pathways of bacteria such as synthesis of cell wall and proteins. Therefore bacteria die due to antibiotic action.

The three limitations which one has to face while dealing with an infectious disease are:

• The body functions are damaged drastically and may never recover completely if not cared.
• The treatment will take time, which means that someone suffering frorti a disease is likely to be bed-ridden for sometime.
• The person suffering from an infectious disease can serve as a source from where the infection may further spread to other people.

Casual organisms of the following diseases:

1. Tuberculosis: Mycobacterium tuberculosis.
2. Kala-azar: Leishmania (protozoa).
3. Malaria: Plasmodium.
4. Measles: Virus.
5. Athlete's foot: Fungi.
6. Cholera: Vibrio Cholerae.

A prolonged bout of diarrhea or vomiting can cause the body to lose more fluid than it can take in. The result is dehydration, which occurs when your body doesn't have the fluid it needs to function properly. Severe dehydration can cause your kidneys to shut down. Though some types of diarrhea, such as those due to other medical conditions, are unavoidable, infectious diarrhea can be prevented. The most important way to avoid diarrhea is to avoid coming into contact with infectious agents that can cause it. This means that good hand washing and hygiene are very important.

There are many disease that are mostly internal and non-infectious. For example, High blood pressure can be caused by excessive weight and lack of exercise. Lack of exercise and excessive add more cholesterol and makes the pressure of blood high. It leads to high blood pressure and causes problem in heart.

Prevention is better than cure as a disease always cause some damage to the body, loss of working days, besides expenditure on medication. The important precautions for preventing occurrence of diseases include.

• Hygienic environment.
• Personal hygiene.
• Proper nutrition.
• Clean food.
• Clean water.
• Regular exercise
• Adequate relaxation.

Everybody should also be aware of diseases and their mode of spreading (epidemic). A regular medical checkup is also earnestly required to stay healthy.

Viruses cause many diseases. Some of the diseases caused by viruses are listed below.

1. Poliomyelitis (polio) is caused by Poliovirus. The symptoms include fever, headache, stiffness or paralysis of limbs. It is mainly transmitted by droplet infection, feces and nasal secretion.
2. Rabies is caused by Rabies virus. The symptoms include headache, nervousness, fever, painful spasms, fear of water (hydrophobia). It is mainly transmitted by bite of infected animal.
3. Jaundice is caused by Hepatitis virus. The symptoms high fever, headache, nausea, vomiting, loss of appetite, dark yellow urine. It is mainly transmitted by contaminated food and water.

The provisions made by local authorities was to allocate funds and guide investments, encourage research, develop human resources through training and other capacity-building efforts, promote water quality monitoring, provide guidelines for various programmes and ensure the implementation of the water supply programmes.

1. Physical inactivity: It is one of the main reasons for many diseases
2. Raised cholesterol: It leads to blocked heart and arteries. It causes damage to cardiac and nervous system
3. Unhealthy diet: Unhealthy diet leads to malnutrition and excess of nutrition. It damages the body parts and bodily functions
4. Raised blood glucose: It leads to diabetes and a person has to rely on medicine throughout life.

1. Immediate Causes: Factors which are directly responsible for a particular disease are called immediate causes.

Example: Pathogens such as virus, bacteria, fungi, etc.

2. Contributory Causes: Factors which provide favourable conditions which make pathogens invasion easy are called contributory causes.

Example: poor nourishment, unhygienic environment, pollutants, etc.

Infectious diseases are transmitted from person to person by direct or indirect contact. Certain types of viruses, bacteria, parasites, and fungi can all cause infectious disease. Malaria, measles, and respiratory illnesses are examples of infectious diseases.

Colds are caused by viruses. When people take them unnecessarily, antibiotics become less effective because bacteria build up a resistance to them. That's why your doctor won't prescribe an antibiotic if you have a common cold. Common cold is caused by a virus and virus do not have a fixed biochemical pathways that is why antibiotics and not able to get into their way.

No the answers to the above questions may not necessarily be the same. This is because a disease free state is not the same as being healthy. Good health is the ability of an individual to realise his or her full potential. Individuals can have poor health without having any identifiable disease. Also, health is related to society and community, whereas having a disease is about an individual sick person. Hence, the conditions for good health and for being disease free can be same or even different.

Because of strong immune system our body is normally fighting off microbes. The immune system possesses specialised cells which are capable of killing the infective microbes. These cells are active when infecting microbes enter the body and if they are successful in removing the pathogen, we remain disease - free. So even if we are exposed to infectious microbes, it does not necessary mean that we suffer from diseases.

There are many provisions provided by local authorities for solid waste management. These are followings:

1. Sweeping.
2. Collection.
3. Vermi-composting.
4. Recycling system.
5. Transportation system.
6. Power generation.
7. Dumping.

Organ Specific Manifestation: These are the diseases caused in the same organ or organ system as the point of entry of the microbe. E.g. Tuberculosis which enters through the nose and affects the lungs. (Both are organs of the respiratory system) Tissue Specific Manifestation: These are the diseases caused in a different organ as the point of entry. E.g. Japanese Encephalitis which enters through the blood but affects the brain.

Vaccines help a body’s immune system prepare in advance to fight infectious illnesses and potentially deadly diseases caused by infectious agents or their by-products. Vaccines work on the principle of immunization. During vaccination, when the immune system first encounters an infectious microbe, it responds against it and then remembers it specifically. So the next time that particular microbe, or its close relatives enter the body, the immune system responds with greater vigour. This eliminates the infection even more quickly than the first occurrence of the disease.

Waterborne diseases are conditions caused by pathogenic micro-organisms that are transmitted in water. Disease can be spread while bathing, washing or drinking water, or by eating food exposed to contaminated water. While diarrhea and vomiting are the most commonly reported symptoms of waterborne illness, other symptoms can include skin, ear, respiratory, or eye problems.

“Prevention of disease is more desirable than its treatment” The three strategies that can be adopted for the prevention of infectious diseases, Maintenance of hygiene and precautions to ward of diseases Proper nutrition to cope with the loss incurred by disease Intake of medicine and proper treatment to stop the disease for ever.

Yes it is true that preventation is more desirable than treatment. It is clear from the following points:

1. Sanitation Keep the environment clean by proper disposal of garbage, sewage and covering, cleaning of drains. This reduces the chance of vector borne disease.
2. Nutrition Well balanced diet full of vital nutrient like carbohydrates, vitamins and mineral should be taken to develop strong immune system. It ultimately kill pathogen even before their multiplication.
3. Proper Exercise and relaxation Proper exercise improves. Blood circulation, tone muscle, improve bowel movement and appetite. While relaxation is necessary for relieving tension and providing rest for muscle. Thus finally all contribute to strong immune system.

An infectious agent is something that infiltrates another living thing, like you. When an infectious agent hitches a ride, you have officially become an infected host.There are four main classes of infectious agents:

1. Bacteria.
2. Viruses.
3. Fungi.
4. Parasites.

Some children have weak immune system which can happen because of various reasons. A child may not be getting balanced diet. A child may be living in congested and unhygienic locality. A child may not be getting clean drinking water. These children are at more risk of falling ill than others living in the same locality.

Tuberculosis: T.B. is an infectious disease which is communicated from one person to another directly or indirectly. It is caused by the bacterium called Mycobacterium tuberculosis. T.B. can affect all parts of the body such as lungs, lymph glands, bones, intestine etc. The incubation period of T.B. includes a few weeks to a few years. The patient of tuberculosis feels sick and weak. There is a loss of appetite and weight. Typical fever pattern and night sweats are also common.

There are two ways to treat an infectious disease. One is to reduce the effects of the disease and the other way is to kill the cause of the disease. For example, we can take the medicines that bring down the fever, reduce pain or loose motions. We can take bed rest so that we can converse our energy. This exercise will enable us to focus on the healing. However it will not make the pathogen to go away, so the disease will not be cured. For that we have to kill the microbe.

A disease can be treated either by reducing the effect of the disease or by killing the cause of the disease. Every infectious disease shows some characteristic symptoms in the form of inflammation, fever or chills. In order to reduce the effect of a disease, one can take medicines. Medicines reduce the symptoms associated with the disease. Symptom-directed treatment does not help to kill pathogens associated with the disease. Pathogenic microbes can be killed by using medicines or antibiotics. The drug used against different groups of pathogens such as bacteria, viruses, protozoa, fungi etc. would be different. The drug or the medicine should kill the pathogen, without affecting the metabolism of the host. Antibiotics can be used to cure bacterial infections as these chemical compounds block the important biochemical pathways of bacteria.

The precautions that one can take in school to reduce the incidence of infectious diseases are:

1. By using handkerchief while coughing sneezing.
2. Washing hands before eating tiffins.
3. Staying at home if anyone suffers from infectious diseases.
4. Getting vaccinated before the infection affects.
5. Keeping the school surroundings clean, checking for stagnant water.

1. Wearing a mask when in contact with a diseased person.
2. Keeping yourself covered while moving around an infected place.
3. Drinking safe water.
4. Eating healthy and nutritious food.
5. Ensuring proper cleanliness and personal hygiene.

Infectious diseases are illnesses that are contagious, meaning they can be spread from one person to another. Infectious diseases are caused by microorganisms, called pathogens, or what we commonly refer to as germs. Viral and bacterial infections are the most common causes of infectious disease. However, fungi and one-celled organisms called protozoa can also be responsible. Flu or influenza Non infectious diseases are illness that are non contagious and cannot spread through contact. Example is Allergy and blood pressure.

Principle of Treatment: There are two ways to treat an infectious disease. One is to reduce the effects of the disease and the other way is to kill the cause of the disease. For the first requirement, we can provide treatments that will reduce the symptoms. The symptoms are usually a result of inflammation. For example, we can take medicines that bring down fever, reduce pain or loose motions. We can take bed rest so that we can converse our energy. However such a kind of symptom-directed treatment by itself is inadequate. Since it will not make the pathogen go away, so the disease will not be cured. For that we have to kill the microbe itself.

There are many possible areas, organs and tissues within our body where microbes may reside. However the severity of disease symptoms depends on the number of microbes in the body. For example, if the number of microbes is very small, then the symptoms of disease will be minor or unnoticed. However, if the numbers are large, the disease can be severe enough to be life-risking.

	Organism/ Bacteria	Disease
a.	Leishmania	Kala-azar
b.	Staphylococci	Acne
c.	Trypanosoma	Sleeping sickness
d.	Ascaris lumbricoides	Worm

A person is more likely to fall sick when she is on a four day fast after recovering from malaria and is taking care of someone who is suffering from chicken pox. This is because she is fasting during recovery, and her immune system is so weak that it is not able to protect its own body from any foreign infection. If she is taking care of someone suffering from chicken pox, then she has more chances of getting infected from chicken pox virus and will get sick again with this disease.

Our health depends on the cleanliness of our surroundings. Flies and mosquitoes carry germs that cause diseases, Flies breed in rotting garbage and mosquitoes breed in pools of stagnant water.
So, people fall ill quite often if the area in which they live or work has uncleaned garbage, pools of stagnant water or open drains. Clean air is also a part of our surrounding and a basic requirement for good health.

Radha might have contracted the disease through sexual contact and blood transfusion. Other infections can affect the eyes, the organs of the digestive system, the kidneys, the lungs, and the brain. Some people develop rare kinds of cancers of the skin or immune system.