Give two examples for each of the following
(a) Acute diseases
(b) Chronic diseases
(c) Infectious diseases
(d) Non-infectious diseases
Soln:
(a) Acute diseases – Flu, Viral fever
(b) Chronic diseases – Tuberculosis, Elephantiasis
(c) Infectious diseases –Small pox, chicken pox
(d) Non-infectious diseases- Diabetes, Cancer
20. Name two diseases caused by Protozoans. What are their causal organisms?
Soln:
Malaria is caused by Plasmodium vivax
Kala-azar is caused by Leishmania
21. Which bacterium causes peptic ulcers? Who discovered the above pathogen for the first time?
Soln:
Peptic ulcers are caused by bacterium Helicobacter pylori. This bacteria was discovered by Barry J. Marshal and Robin Warren.
22. What is an antibiotic? Give two examples
Soln:
An antibiotic is a chemical agent that kills the bacteria or fungi by blocking their biochemical pathway. Ex: Streptomycin, Azithromycin.
23. Fill in the blanks
(a) Pneumonia is an example of ——— disease.
(b) Many skin diseases are caused by———.
(c) Antibiotics commonly block biochemical pathways important for the growth of ———.
(d) Living organisms carrying the infecting agents from one person to another are called ———.
Soln:
(a) Pneumonia is an example of Bacterial disease.
(b) Many skin diseases are caused by Fungi.
(c) Antibiotics commonly block biochemical pathways important for the growth of Bacteria.
(d) Living organisms carrying the infecting agents from one person to another are called Vectors.
24. Name the target organs for the following diseases
(a) Hepatitis targets———.
(b) Fits or unconsciousness targets ———.
(c) Pneumonia targets ———.
(d) Fungal disease targets ———.
Soln:
(a) Hepatitis targets Liver.
(b) Fits or unconsciousness targets Brain.
(c) Pneumonia targets Lungs.
(d) Fungal disease targets Skin.
25. Who discovered ‘vaccine’ for the first time? Name two diseases which can be prevented by using vaccines.
Soln:
Edward Jenner discovered the vaccine. Polio and tetanus are the diseases which can be prevented by using vaccines.
26. Fill in the blanks
(a) ——— disease continues for many days and causes——— on body.
(b) ———disease continues for a few days and causes no long term effect on body.
(c) ——— is defined as physical, mental and social well-being and comfort.
(d) Common cold is——— disease.
(e) Many skin diseases are caused by———.
Soln:
(a) Chronic disease continues for many days and causes long term effect on body.
(b) Acute disease continues for a few days and causes no long term effect on body.
(c) Health is defined as physical, mental and social well-being and comfort.
(d) Common cold is a viral disease.
(e) Many skin diseases are caused by Fungi.
27. Classify the following diseases as infectious or non-infectious.
(a) AIDS
(b) Tuberculosis
(c) Cholera
(d) High blood pressure
(e) Heart disease
(f) Pneumonia
(g) Cancer
Soln:
(a) AIDS – Infectious disease
(b) Tuberculosis – Infectious disease
(c) Cholera – Infectious disease
(d) High blood pressure – non-Infectious disease
(e) Heart disease non – Infectious disease
(f) Pneumonia – Infectious disease
(g) Cancer – non-Infectious disease
28. Name any two groups of micro-organisms from which antibiotics could be extracted.
Soln:
Bacteria and fungi
29. Name any three diseases transmitted through vectors.
Soln:
Malaria transmitted by mosquitos
Rabies transmitted by mad dogs
Elephantiasis is transmitted by mosquitos.
30. Explain giving reasons
(a) Balanced diet is necessary for maintaining healthy body.
(b) Health of an organism depends upon the surrounding environmental conditions.
(c) Our surrounding area should be free of stagnant water.
(d) Social harmony and good economic conditions are necessary for good health.
Soln:
a) Food is essential for the growth and normal functioning of our body. A balanced diet is the one which consists of all the essential nutrients in an appropriate quantity. A balanced diet provides an appropriate amount of biomolecules such as carbohydrates, lipids, proteins, vitamins and minerals which are very essential for our growth and body functioning. Imbalance in the diet leads to many physical and physiological disorders.
b) Health is defined as physical, mental and social well-being and comfort. Health is always dependent on our surroundings and if our environment is unhygienic we get a disease. We get cold and cough in rainy and winter season. Our environmental conditions are very important for being healthy.
c) Stagnant water is the breeding ground for mosquitos. Mosquitos spread many diseases like Malaria, Dengue, Elephantiasis, chikungunya etc. In order to stop the spread of these diseases, our surroundings should be free of stagnant water.
d) Human beings are social organisms. We live in different localities and environments. In order to lead a healthy life, we have to keep our environment clean. We need hygienic food to lead a healthy life which depends on our economic conditions. We often encounter diseases, in order to get the treatment we need the money and our economic status should be strong to afford the treatments.
31. What is a disease? How many types of diseases have you studied? Give examples.
Soln:
Each organ of an organ system has specific functions to do. When this functioning changes or disrupts it leads to a condition called disease. These changes result in some adverse effects on the body’s normal functioning and the changes observed are called signs and symptoms of the disease.
Types of Diseases
Acute:
Diseases that last for only very short periods of time are called acute diseases. Ex: common cold
Chronic:
Diseases that last for a long time, even as much as a lifetime are called chronic diseases. Ex: elephantiasis.
Infectious:
Diseases which are caused by microorganisms are called infectious diseases. These diseases can spread from one person to another by vectors or by other means such as air, food and water. Ex: Typhoid
Non-Infectious:
Diseases that are not caused by infectious agents. Their causes vary, but they are not external causes like microbes that can spread in the community. Instead, these are mostly internal, non-infectious causes. Example: High blood pressure.
32. What do you mean by disease symptoms? Explain by giving two examples.
Soln:
When our body encounters a disease, it results in the abnormal functioning of the body. These abnormal functions are known as symptoms.
For eg., a malaria patient would include symptoms such as high fever with shaking chills, headache, vomiting, nausea, abdominal pain, diarrhoea, etc.
A tuberculosis patient would exhibit symptoms such as fever, chills, loss of appetite, blood in the cough, chest pain, etc.
33. Why is the immune system essential for our health?
Soln:
The immune system is the line of our body. The immune system comprises different kinds of cells that kill the infecting microorganism. When a pathogen enters our body, antibodies are released in response to the pathogen. These antibodies kill pathogens and prevent us from illnesses.
34. What precautions will you take to justify “prevention is better than cure”.
Soln:
Precautions taken to avoid diseases are as follows
- Maintaining personal as well as public hygiene
- Awareness about causes, symptoms and the source of diseases
- Using clean water and avoid storage of water to avoid the growth of mosquitos
- Balanced diet
- Regular exercise to boost the immunity
- Vaccination
35. Why do some children fall ill more frequently than others living in the same locality?
Soln:
Some of the reasons are listed below.
- Lack of balanced diet leading to malnutrition
- Weak immunity
- Living in congested, unhygienic conditions
- Lack of clean drinking water and hygienic food
- Missing vaccinations
36. Why are antibiotics not effective for viral diseases?
Soln:
Antibiotics act on bacteria and fungi by blocking certain biochemical activities necessary for the living of bacteria. On the other hand, the virus uses the host machinery for survival and replication. Hence, antiviral drugs work differently to antibiotics. They interfere with the viral enzymes to destroy them.
37. Becoming exposed to or infected with an infectious microbe does not necessarily mean developing a noticeable disease. Explain.
Soln:
Our immune system fights disease-causing pathogens and clears them by killing to give us protection from disease. When we get exposed to certain pathogen our immune system sends active cells that kill and clear the pathogen. Owing to our immune system, we don’t often get the disease despite getting exposed to the infectious microbe.
38. Give any four factors necessary for a healthy person.
Soln:
Hygienic environment:
Clean water and a hygienic surrounding can keep us away from water and airborne diseases.
Personal Hygiene:
We should keep our body clean to be healthy.
Food:
Hygienic and nutritious food help to boost the immune system hence a balanced diet is essential for being healthy.
Vaccination:
Vaccination against severe disease is very essential to be healthy.
39. Why is AIDS considered to be a ‘Syndrome’ and not a disease?
HIV AIDS is caused by HIV Virus, which enters our body through body fluids such as blood and breast milk or by sexual means. HIV virus spreads to lymph nodes and it blocks our immune system. This creates a condition where our body cannot fight minor diseases like common cold.
A person with HIV can get pneumonia from the common cold, the minor gut infection may turn into severe diarrhoea. In HIV a person will not have specific symptoms rather he will have a series of infections. Hence HIV is called a syndrome, not a disease.
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