Q 1. What is meant by symptoms of a disease?
Ans. The conditions in which a sick person experience headache, watering of eyes, loose motions, are collectively called the symptoms of a disease.
Q 2. Define reservoir.
Ans. A reservoir is defined as any person, animal, arthropod, plant, soil or substance in which an infectious agent lives and multiplies for its primary survival.
Q 3. What is a source of infection?
Ans, Person, animal, object or substance from which an infectious agent passes or is disseminated to the host is known as the source of infection.
Q 4. How can we diagnose a disease?
Ans. By laboratory tests.
Q 5. What is community health?
Ans. It is the personal health along with the environmental services for the importance of health of the community.
Q 6. What does WHO stand for?
Ans. World Health Organisation.
Q 7. How can dehydration of the body be prevented?
Ans. Dehydration can be prevented by intake of ORS (Oral Rehydration Solution).
Q 8. How does WHO define health?
Ans. WHO defines health as a state of complete physical, mental and social well-being and not merely an absence of disease or infirmity.
Q 9. Classify diseases on the basis of their time of occurrence.
Ans. Congenital diseases and acquired diseases.
Q 10. What are congenital diseases?
Ans. The diseases which are present from the time of birth and are hereditary are called congenital diseases.
Q 11. Write the name of a disease that spreads through direct contact.
Ans. Leprosy
Q 12. Why is rabies also called as hydrophobia?
Ans. Rabies is also called as hydrophobia because its main symptom is fear of water.
Q 13. Name the disease-causing microbe that lives and remains active inside the host cell.
Ans. Virus
Q 14. Against what disease BCG vaccine is given?
Ans. Tuberculosis
Q 15. What are vectors?
Ans. The organisms that act as intermediaries and carry the infectious agents from a sick person to a potential host are called vectors.
Q 16. Name the vector of malaria.
Ans. Female Anopheles mosquito.
Q 17. What do you mean by immune system?
Ans. The system in our body which protects us from the various disease-causing agents is called immune system.
Q 18. Expand AIDS.
Ans. Acquired Immuno Deficiency Syndrome
Q 19. Expand HIV.
Ans. Human Immunodeficiency Virus.
Q 20. What is the incubation period of hepatitis B?
Ans. 45 to 185 days
Q 21. How can AIDS be transmitted?
Ans. AIDS can be transmitted through sexual intercourse, use of contaminated syringes as well as by transfusion of contaminated blood.
Q 22. When is World AIDS Day observed?
Ans. On 1 st December
Q 23. What is immunity?
Ans. Immunity is the ability of the body to defend against a disease.
Q 24. Deficiency of which vitamin causes xerophthalmia.
Ans. Vitamin A
Q 25. xpand OPV.
Ans. Oral Polio Virus vaccine
Q 26. Give the name of two diseases which result from protein malnutrition.
Ans. Kwashiorkor and marasmus
Q 27. What is the cause of the disease beri-beri?
Ans. Deficiency of water-soluble vitamin B1 (thiamine) causes beri-beri.
Q 28. Give the full form of PEM.
Ans. Protein Energy Malnutrition
Q 29. What is the function of haemoglobin?
Ans. Transport of oxygen from lungs to all cells of the body through blood.
Q 30. Name the mineral present in haemoglobin.
Ans. Iron
Q 31. Name the fat-soluble vitamins.
Ans. Vitamin A, D, E and K are fat soluble.
Q 32. Name the disease caused by the deficiency of iodine.
Ans. Goitre
Q 33. While going abroad why is it essential to get vaccinated against certain diseases?
Ans. A person may be a carrier of a disease, such a person can carry the disease to a foreign country. To avoid this the person is vaccinated.
Q 34. What is the method of transmission of the disease cholera?
Ans. Contaminated water
Q 35. Which vitamin is formed by the body with the help of sunlight?
Ans. Vitamin D
Q 36. Name the disease caused by the deficiency of vitamin ?
Ans. Rickets
Q 37. Name the disease which causes swollen and bleeding gums.
Ans. Scurvy
Q 38. What is the name of the disease that occurs in people who eat polished rice everyday?
Ans. Beri-beri
Q 39. Why should not vegetables and pulses be washed repeatedly for a long tithe?
Ans. Repeated washing of vegetables and pulses results in depletion of vitamin C which is a water- soluble vitamin.
Q 40. What is an antibiotic? Give two examples.
Ans. Antibiotic is a chemical substance secreted by microorganisms which can kill bacteria. For example, penicillin and streptomycin.
Q 41. Name any two groups of microorganisms from which antibiotics could be extracted.
Ans. Bacteria and fungi
Q 42. Who discovered ‘vaccine’ for the first time? Name two diseases which can be prevented by using vaccines.
Ans. Edward Jenner discovered vaccine for the first time. Small pox and polio can be prevented by using vaccines.
Q 43. What is a balanced diet?
Ans. A balanced diet is the one which contains a variety of foods in such quantities and proportions that the need for energy, amino acids, vitamins, minerals, water and roughage is adequately met for maintaining health, vitality and general well being.
Q 44. Why is immune system essential for our health?
Ans. The immune system of our body is a defence mechanism to fight against pathogenic microbes. It has cells that are specialised to kill infecting microbes and keep our body healthy. If the body’s immune system is strong, it can easily fight pathogens, keeping us healthy.
Q 45. Why is mother’s milk best for babies?
Ans. Mother’s milk is rich in proteins and other nutrients. It provides a complete diet to the baby.
Q 46. What are the two basic principles of prevention of infectious diseases?
Ans. The two basic principles of prevention of infectious diseases are:
- Prevention from exposure to infectious microbes.
- Provision of proper nutrition to keep the immune system in a healthy state.
Q 47. What is the mechanism of action of antibiotics?
Ans. Antibiotics are chemical substances obtained from some microbes, which stop the growth of specific kind of pathogens. They block certain biochemical pathways important for the lifecycle of pathogen. For example, penicillin does not allow cell wall formation in some bacteria. It blocks chemical reaction required for cell wall formation.
Q 48. Public cleanliness is important for individual health’. Comment.
Ans. The garbage thrown in open places, overflowing drains or sewer water, stagnant water, etc. are the places where disease-causing microbes multiply and mosquitoes and flies breed. These mosquitoes and flies act as carriers of disease-causing microbes. As a result, diseases may spread in the community and affect individual health. Thus, public cleanliness is important for individual health.
Q 49. Why is vaccination considered a prevention of diseases?
Ans. Vaccines induce a specific immune response in the body. This response also produce memory cells which persist in the body even in the absence of pathogen. If the pathogen attacks the body again, the immune system with the help of memory cells recognise it and destroy it before it causes the disease..
Q 50. Why is social equality necessary for individual health?
Ans. If the mind is cheerful and happy, people are not prone to tensions. Moreover, as they are not disturbed, they will take care about doing anything which affects their health. On the other hand, if people are socially disturbed and unsafe, they cannot be happy and healthy. So, social equality is necessary for individual health.