Aids to Health - Questions & Answers

1. Give one example of each of the following :
(i) Germ-killing body secretion.
Tears (or Saliva, Hydrochloric acid in stomach)
(ii) Germ-trapping body secretion.
Mucus
(iii) Mechanical barrier that prevents the entry of germs into the body.
Skin (or Hairs in nostrils)

2. Mention if the following statements are True (T) or False (F)
(i) Immune system deals with the germs after they have entered the body.
True (T)
(ii) Antibodies eat up the germs.
False (F)
(iii) Human beings can suffer from all those diseases which attack dogs.
False (F)
(iv) Anti-venin injection against snake bite is an example of artificially acquired passive immunity.
True (T)
(v) Mother's antibodies may reach the foetus through placenta.
True (T)
(vi) A person having once suffered from measles usually gets repeated attacks.
False (F)

1. Define the term prophylaxis.
Vaccination is the practice of artificially introducing the germs or the germ substance into the body for developing resistance to particular diseases. Scientifically, this practice is called prophylaxis.

2. Name the four categories of materials used for preparing vaccines.
(1) Killed germs, (2) Living weakened germs, (3) Living fully poisonous germs, and (4) Toxoids.

3. Name the diseases prevented by :
(i) Salk's vaccine
Poliomyelitis (Polio)
(ii) BCG vaccine
Tuberculosis
(iii) DPT vaccine
Diphtheria, Pertussis (whooping cough), and Tetanus

1. Correct the following statements if they are false (without changing the first word).
(i) DDT is an antiseptic.
DDT is a disinfectant.
(ii) Penicillin is a disinfectant.
Penicillin is an antibiotic.
(iii) Disinfectants are applied on the body.
Disinfectants are applied on spots and places where germs thrive and multiply.
(iv) Deodorants are both antiseptic as well as disinfectants.
Deodorants are neither antiseptics nor disinfectants (they only serve to mask a bad smell).
(v) Alexander Fleming discovered the first sulphonamide.
Alexander Fleming discovered the first antibiotic (Penicillin).
(vi) Antibiotics cannot be made synthetically.
Antibiotics can be made synthetically.
(vii) Sulphonamides are now rarely used.
Sulphonamides are now rarely used. (The statement is already correct).

2. List any three uses of antibiotics.
1. In medicine to fight human infections.
2. As food preservatives, especially for fresh meat and fish.
3. Treating animal feed to prevent internal infections.

1. Choose the correct answer from the options given below :
(i) Penicillin is :
(a) an antiseptic (b) a disinfectant (c) an antibiotic (d) an antitoxin
(c) an antibiotic

(ii) Which of the following immunity is present from our birth ?
(a) Innate immunity (b) Active immunity (c) Passive immunity (d) Acquired immunity
(a) Innate immunity

(iii) Naturally acquired active immunity would be most likely acquired through which of the following processes ?
(a) vaccination (b) drinking colostrum (c) natural birth (d) previous infection with a disease - causing organism
(d) previous infection with a disease - causing organism

(iv) DPT stands for :
(a) Diphtheria, Polio and Tetanus (b) Diphtheria, Pertussis and Tetanus (c) Dysentery, Polio and Typhoid (d) Diphtheria, Polio and Typhoid .
(b) Diphtheria, Pertussis and Tetanus

(v) Vaccines are :
(a) An extract of toxins secreted by bacteria. (b) An extract of dead and weakened microbes. (c) Strong chemicals obtained from fungi. (d) Chemicals that are applied on the skin to kill bacteria
(b) An extract of dead and weakened microbes.

(vi) The letter "B" in the name BCG vaccination stands for :
(a) Brief (b) Beri-beri (c) Bacteria (d) Bacillus
(d) Bacillus

(vii) The body's defense against diseases is termed as :
(a) Hygiene (b) Immunity (c) Health (d) None of these
(b) Immunity

(viii) The slimy secretion of the epithelial lining of the various organs is called :
(a) Antiseptic (b) Antibodies (c) Both (a) & (b) (d) Mucus
(d) Mucus

(ix) Which of the following is not a germ-killing secretion?
(a) Blood (b) Saliva (c) Tears (d) Sweat
(a) Blood

(x) Antibody is a blood serum protein produced in response to :
(a) Antitoxins (b) Antibiotics (c) Antigens (d) Antiseptics
(c) Antigens

(xi) A biology teacher asked her students to give two examples of antiseptics, which can be used to kill germs.
Prerna said : Boric acid and 40% Formalin.
Shreya said : Benzoic acid and Bordeaux mixture.
Rahul said : Carbolic acid and Boric acid.
Rishi said : Mercurochrome and Benzoic acid.
Who were correct ?
(a) Prerna and Shreya (b) Shreya and Rahul (c) Rahul and Rishi (d) Rishi and Prerna
(c) Rahul and Rishi

1. Name the following :
(a) The drug based on arsenic compound, produced in 1910 which killed germs of syphilis.
Salvarsan
(b) The antibiotic that was discovered first.
Penicillin
(c) The category of immunity required in the treatment of snakebite.
Artificially acquired passive immunity
(d) The medicines made by the combination of penicillin and sulpha drugs.
Pentidsulph
(e) The scientist who discovered the first antibiotic.
Alexander Fleming

2. Write the full forms of the following abbreviations:
(a) AIDS Acquired Immuno Deficiency Syndrome
(b) BCG Bacillus of Calmette and Guérin
(c) DPT Diphtheria, Pertussis and Tetanus
(d) DDT Dichloro-Diphenyl-Trichloroethane
(e) WHO World Health Organization
(f) HIV Human Immunodeficiency Virus
(g) STD Sexually Transmitted Disease
(h) WBC White Blood Cell
(i) TAB Typhoid and Paratyphoid A & B Vaccine
(j) COVID-19 Coronavirus Disease 2019

3. Name :
(a) Five antiseptics
Lysol, carbolic acid, iodine, benzoic acid, mercurochrome
(b) Five disinfectants
Cresol, phenol, 40% formalin, lime, bordeaux mixture
(c) Two antibiotics
Penicillin, Streptomycin
(d) Two sulpha drugs
Sulphadiazine, Sulphanilamide
(e) Two sexually transmitted diseases
Gonorrhea, Syphilis

1. Define the terms :
(a) Immunity
Immunity is the resistance to the onset of a disease after infection by harmful germs, or the capacity of our body to deal with foreign substances and render them harmless.
(b) Antibodies
Antibodies are special chemical proteins (immunoglobulins) produced in the blood in response to injected antigens which act against the germs or their secretions.
(c) Prophylaxis
The practice of artificially introducing the germs or the germ substance into the body for developing resistance to particular diseases.
(d) Vaccine
Vaccine is the material (dead or weakened germs) introduced into the body of a living being to develop immunity (resistance) against the respective disease or diseases.
(e) Immunisation
Developing resistance to disease-producing germs or their toxins by introducing killed germs or germ substances to induce the production of specific antibodies.

2. Correct the following statements by changing the first/last word only :
(a) Lysol is an antibiotic.
Lysol is an antiseptic.
(b) The treatment of diseases by the use of chemical substances is known as allopathy.
The treatment of diseases by the use of chemical substances is known as chemotherapy.
(c) RBCs are germ -fighting cells of our body.
WBCs are germ-fighting cells of our body.
(d) Antiseptics are the proteins that belong to the class of immunoglobulins.
Antibodies are the proteins that belong to the class of immunoglobulins.
(e) BCG vaccines are given to small babies orally.
Polio vaccines are given to small babies orally.

3. Given below is a table of certain vaccines, the diseases against which they are used and the nature of vaccine. Fill up the gaps 1 - 10.

4. Choose the odd one out and write the category for the remaining terms.
(a) Carbolic acid, Formalin, Benzoic acid, Boric acid
Odd one: Formalin. Category: Antiseptics.
(b) Mercurochrome, Cresol, Phenol, Bordeaux mixture
Odd one: Mercurochrome. Category: Disinfectants.
(c) ATP, DPT, BCG, TAB
Odd one: ATP. Category: Vaccines.
(d) Saliva, Sweat, Skin, Tears
Odd one: Skin. Category: Germ-killing secretions.
(e) Chloromycetin, Streptomyces, Streptomycin, Aureomycin
Odd one: Streptomyces. Category: Antibiotics.

5. List any four ways in which the antibiotics are being used.
1. In medicine to fight infections.
2. As food preservatives, especially fresh meat and fish.
3. In treating animal feed to prevent internal infections.
4. Controlling plant pathogens.

6. List the merits of local defence systems.
1. They start working instantaneously.
2. They are not dependent on previous exposure to infections.
3. They are effective against a wide range of potentially infectious agents.

7. Given below is a scheme of classifying immunity against human diseases. Fill up the types of immunity in the blanks 1-9.

1. Innate (Inborn/natural)
2. Acquired (Develops during life time)
3. Non-specific (General defence mechanisms)
4. Active (Produced by one's own body)
5. Passive (Supplied from outside sources)
6. Natural (By previous infections)
7. Artificial (by vaccinations)
8. Natural (Antibodies received from the mother through placenta/milk)
9. Artificial (Readymade antibodies produced in other animals)

1. Differentiate between :
(a) Antiseptic and antibiotic,
Antiseptics are mild chemical substances applied externally on the body to kill germs. Antibiotics are chemical substances produced by some microorganisms that kill or inhibit the growth of other microorganisms inside the body.
(b) Antiseptic and disinfectant,
Antiseptics are mild germ-killing substances applied on the living body that cause no harm to the skin. Disinfectants are strong germ-killing substances applied on spots and places which may cause harm to the skin and body.
(c) Disinfectant and deodorant,
Disinfectants are strong chemicals that kill germs thriving on surfaces. Deodorants are neither antiseptics nor disinfectants; they only serve to mask a bad smell without killing germs.
(d) Vaccination and sterilisation
Vaccination is the introduction of dead or weakened germs into the body to develop immunity against diseases. Sterilisation (using strong heat or boiling) acts as a physical disinfectant to destroy and completely eliminate germs from objects.
(e) Active immunity and passive immunity,
Active immunity is produced by one's own body upon infection or vaccination and provides long-lasting protection. Passive immunity is provided by ready-made antibodies from an outside source, offering immediate but temporary protection.
(f) Innate immunity and acquired immunity.
Innate immunity is an inborn, natural resistance present from birth by virtue of genetic makeup. Acquired immunity is the resistance to a disease which an individual acquires during their life-time.

2. The principle of vaccination is to produce immunity against a disease. Explain.
Vaccination introduces dead or weakened germs (vaccine) into the body. This safely stimulates the white blood cells to produce specific antibodies against those germs. These antibodies provide active immunity, and the memory lymphocytes ensure long-lasting protection if the actual disease germs invade the body in the future.

3. "Abnormally large number of WBCs in the blood are usually an indication of some infection in our body." Comment on the statement. (LS)
White Blood Cells (WBCs) are the body's primary defense against invading germs. When an infection occurs, the immune system triggers a rapid multiplication and deployment of WBCs (phagocytes and lymphocytes) to engulf the germs (phagocytosis) and produce antibodies. Therefore, a high WBC count indicates the body is actively fighting off an infection.

4. Explain briefly, the role of the following health aids:
(a) Antiseptics (b) Disinfectants (c) Vaccines.
(a) Antiseptics: Applied on the skin to prevent infection of cuts and wounds by safely killing germs without harming living tissues.
(b) Disinfectants: Used to kill germs multiplying on surfaces, spots, and objects, thereby preventing the spread of diseases.
(c) Vaccines: Introduced into the body to proactively develop immunity (antibodies) against specific infectious diseases.

5. Suppose a person develops the disease diphtheria. Comment upon the principle of the treatment he should receive.
Since the person has already developed the disease, they should receive artificially acquired passive immunisation. This involves injecting pre-prepared antibodies (like anti-diphtheria injections or antitoxin) produced in another animal. This ready-made supply provides immediate, though temporary, defense to neutralize the diphtheria toxins.

6. Why is it important to know how the germs leave the body of a patient ?
Knowing how germs leave a patient's body (e.g., via coughing, sneezing, or excretions) is crucial for controlling the spread of the disease. It allows us to apply targeted preventive measures, such as using correct disinfectants on waste or isolating specific body fluids, preventing healthy individuals from catching the disease.

1. The figures A, B and C given below represent a kind of protective method in our body. Study the same and answer the following questions :
(a) Name and define the process which occurs in figure A.
Diapedesis. It is the process by which white blood cells squeeze out of the walls of the blood capillaries into the tissues.
(b) What kind of blood vessel is shown in figure-A? Write its one specific structural feature.
Capillary. Its specific structural feature is a very thin wall (single cell thick) that allows WBCs to squeeze through.
(c) Name and define the process occurring in figure-B.
Phagocytosis. It is the process of a white blood cell engulfing and destroying bacteria or germs.
(d) What kind of blood cell is shown in the figures? Write its technical name also.
White blood cell. Its technical name is Leucocyte (specifically a Phagocyte).
(e) Name the specific type of cell containing a 4 lobed nucleus of the category answered by you in part (d) above.
Neutrophil.

2. The figures given below show a kind of antibiotic prepared from a microbe. Antibiotics are used to kill or inhibit the growth of microorganisms. Answer the following questions.
(a) What are the two kinds of microbes used to prepare antibiotics ?
Fungi (moulds) and bacteria.
(b) Name the scientist who discovered the first antibiotic.
Alexander Fleming.
(c) Write the scientific name of the source from which the first antibiotic was produced.
Penicillium notatum.
(d) Give two examples of antibiotics.
Penicillin and Streptomycin.
(e) Mention one use of the above mentioned antibiotic other than in medical treatment.
Used as food preservatives (especially for fresh meat and fish).

(Choose the answer based on the codes given below.)
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

(i) Assertion (A) : Immunity is the resistance to the onset of a disease after infection by harmful germs.
Reason (R) : A body's immunity is maintained by two proteinaceous substances — antigens and antiseptics.
(c) A is true but R is false.

(ii) Assertion (A) : Antibodies are produced by a type of specialised lymphocytes on exposure to antigens. Thus antibodies are protective elements of our blood.
Reason (R) : Antibodies recognise a particular antigen and binds to it rendering it harmless. Thus antibodies protect us from disease-causing germs.
(a) Both A and R are true and R is the correct explanation of A.

(iii) Assertion (A) : The vaccine for tuberculosis is made up of living, weakened germs.
Reason (R) : Living, weakened germs in the vaccine were not satisfactory to prevent the disease.
(c) A is true but R is false.

(iv) Assertion (A) : Active immunity is produced by one's own body.
Reason (R) : Active immunity is induced by infection or by contact with immunogens.
(a) Both A and R are true and R is the correct explanation of A.

(v) Assertion (A) : Both antiseptics and disinfectants are used to kill germs which can cause several diseases.
Reason (R) : Antiseptics destroy germs from the surface of the body whereas disinfectants destroy germs from inside the body of living beings.
(c) A is true but R is false.

1. After suffering from sore throat and fever from several days, Avinash visited a doctor who confirmed that his illness was caused by a bacterial infection. The doctor prescribed antibiotics, and within two days he started feeling much better. His sister however, once took an antibiotic on her own for a common cold and saw no improvement because colds are caused by viruses. Their mother explained that antibiotics work only against bacterial diseases and not viral ones.
(a) What antibiotic was discovered for the first time? Name the scientist who discovered it.
Penicillin. Discovered by Alexander Fleming.
(b) Write the scientific name of the mould from which the first antibiotic was extracted.
Penicillium notatum
(c) Write two more uses of antibiotics, other than being used in medicines.
Used as food preservatives and for treating animal feed to prevent internal infections.
(d) Besides moulds, which other category of organisms is widely used to obtain certain kinds of antibiotics ?
Bacteria (e.g., Streptomyces)
(e) Name the vaccine which can be used to prevent the bacterial disease — tuberculosis.
BCG (Bacillus Calmette-Guérin) vaccine