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Chapter 17

Aids to Health

Class 9 - Concise Biology Selina

Multiple Choice Type

Question 1

Penicillin is

  1. an antiseptic
  2. a disinfectant
  3. an antibiotic ✓
  4. an anti-toxin

Question 2

"T" in DTP vaccination stands for

  1. Tuberculosis
  2. Typhoid
  3. Tetanus ✓
  4. Tonsillitis

Question 3

World Health Day is celebrated on

  1. April 7 ✓
  2. February 21
  3. October 10
  4. January 15

Question 4

DTP stands for

  1. Diphtheria, Polio and Tetanus
  2. Diphtheria, Pertussis and Tetanus ✓
  3. Dysentery, Polio and Typhoid
  4. Diphtheria, Polio and Typhoid

Question 5

Vaccines are:

  1. An extract of toxins secreted by bacteria
  2. An extract of dead and weakened microbes ✓
  3. Strong chemicals obtained from fungi
  4. Chemicals that are applied on the skin to kill bacteria.

Question 6

The letter "B" in the name BCG vaccination stands for:

  1. Brief
  2. Beri-beri
  3. Bacteria
  4. Bacillus ✓

Very Short Answer Type

Question 1(a)

Name the following:

The drug based on arsenic compound, produced in 1910 which killed germs of syphilis.


Salvarsan and Arsphenamine

Question 1(b)

Name the following:

The antibiotic that was discovered first.



Question 1(c)

Name the following:

The category of immunity required in the treatment of snake-bite.


Passive acquired immunity

Question 1(d)

Name the following:

Any four antiseptics, any two disinfectants and any two antibiotics.


Antiseptics — Carbolic acid, Lysol, Boric acid, Iodine

Disinfectants — Cresol, phenol

Antibiotics — Penicillin, Ampicillin

Question 1(e)

Name the following:

The vaccines that help to produce immunity against Polio.


Oral polio vaccine (OPV)

Question 2

Write the full forms of:

(i) AIDS

(ii) BCG

(iii) DPT vaccine

(iv) WHO

(v) HIV

(vi) ATS

(vii) TAB

(viii) STD


(i) AIDS — Acquired Immuno Deficiency Syndrome

(ii) BCG — Bacillus Calmette Guerin

(iii) DPT vaccine — Diphtheria Pertussis and Tetanus vaccine

(iv) WHO — World Health Organization

(v) HIV — Human Immunodeficiency virus

(vi) ATS — Anti Tetanus Serum

(vii) TAB — Typhoid Paratyphoid A & B

(viii) STD — Sexually Transmitted Disease

Question 3

Give the technical term for the kind of proteins produced in the blood to fight and destroy harmful microbes.


Antibodies is the technical term for the proteins produced in the blood to fight and destroy harmful microbes. They are the immunoglobulin produced in the blood to protect the body against harmful microbes.

Short Answer Type

Question 1

Mention if the following statements are true (T) or false (F).

(a) Lysol is an antibiotic

(b) Sweat and tears contain germs-killing substances

(c) Our body can make only a limited variety of different antibodies

(d) Salk vaccine is used against tuberculosis

(e) Treatment by the use of chemicals is known as allopathy

(f) Alexander Fleming coined the term “antibiotic” for substances like penicillin

(g) DDT is a disinfectant.

(h) Vaccine provides the body with Active Immunity

(i) Penicillin was discovered by Alexander Fleming

(j) BCG is the vaccine given to babies to help build immunity against three common diseases

Question 2

Differentiate between:

(a) Antiseptic and antibiotic

(b) Antiseptic and disinfectant

(c) Disinfectant and deodorant

(d) Vaccination and sterilization

(e) Active Immunity and passive immunity

(f) Innate immunity and acquired immunity


(a) Antiseptic and Antibiotic

It is a mild chemical substance applied to the body to kill germs.It is a chemical substance produced by the microbes which kills or hinders the growth of microbes.

(b) Antiseptic and Disinfectant

These are mild chemical substances which, when applied on the body, kill germs. These substances cause no harm to the skin and body.These are strong chemical substances that are applied on spots and places where germs thrive and multiply.

(c) Disinfectant and Deodorant

These are strong chemical substances that are applied on spots and places where germs thrive and multiply.They are neither antiseptics nor disinfectants. They are used to mask bad smell and are aerosols.

(d) Vaccination and Sterilization

It is the practice of artificially introducing the germs or the germ substance into the body for developing resistance to particular diseases.Process of elimination of microbes from a surface contained in a fluid, in compound such as biological culture media or in medication.

(e) Active immunity and Passive immunity

Active ImmunityPassive Immunity
Developed by an individual due to a previous infection or antigen which naturally enters the body.Immunity provided to an individual from an outside source as readymade antibodies.

(f) Innate immunity and Acquired immunity

Innate ImmunityAcquired Immunity
It is the immunity by the virtue of genetic constitutional makeup, i.e. it is inherited from parents. It is present in the body without any external stimulation or a previous infection.It is the resistance to a disease the body acquires in his lifetime.

Question 3

Name any three vaccines and the diseases for which they provide immunity.


  1. TAB vaccine for Typhoid.
  2. Salk’s vaccine for Poliomyelitis
  3. BCG vaccine for Tuberculosis

Question 4

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.

VaccineDisease(s)The nature of vaccine
TAB1. __________2. __________
Salk’s vaccine3. __________4. __________
BCG5. __________Living weakened germs
Vaccine for measlesMeasles6. __________
Cowpox virus7. __________8. __________
Toxoids9. __________ and
10. __________
Inactivated toxins
secreted by bacteria


VaccineDisease(s)The nature of vaccine
TAB1. Typhoid2. Killed germs
Salk’s vaccine3. Poliomyelitis4. Killed germs
BCG5. TuberculosisLiving weakened germs
Vaccine for measlesMeasles6. Living weakened germs
Cowpox virus7. Small pox8. Living fully poisonous germs
Toxoids9. Diphtheria and
10. Tetanus
Inactivated toxins
secreted by bacteria

Question 5

Given below are the groups of certain substances of particular categories. Mention the category of each group and identify the wrong example giving reason.

(a) Lysol, benzoic acid, DDT, mercurochrome.

(b) Formalin, iodine, lysol, phenol

(c) BCG, DTP, ATP.

(d) Tears, skin, nasal secretion, HCl (in stomach)


(a) Lysol, benzoic acid, DDT, mercurochrome.
The category of this group is Antiseptics. DDT is a wrong example as all others are antiseptics but DDT is a disinfectant which cannot be applied on the skin.

(b) Formalin, iodine, lysol, phenol.
The category of this group is Disinfectants. Iodine is a wrong example as all others are disinfectants where as Iodine is an antiseptic.

(c) BCG, DTP, ATP.
The category of this group is Vaccines. ATP is a wrong example as it is an energy carrier in the cells of all known organisms whereas BCG, DTP are vaccines.

(d) Tears, skin, nasal Secretion, HCl (in stomach)
The category of this group is Germ killing secretions. Skin is a wrong example as it is a protective mechanical barrier preventing the entry of germs in our body whereas the others are germ killing secretions.

Question 6

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

Given below is a scheme of classifying immunity against human diseases. Fill up the types of immunity in the blanks 1-9. Aids to health, Concise Biology Selina Solutions ICSE Class 9.


  • 1 → Innate Immunity
  • 2 → Acquired Immunity
  • 3 → Specific Immunity
  • 4 → Active acquired Immunity
  • 5 → Passive acquired Immunity
  • 6 → Natural acquired active Immunity
  • 7 → Artificial acquired active Immunity
  • 8 → Natural acquired passive Immunity
  • 9 → Artificial acquired passive Immunity

Question 7

List any four ways in which the antibiotics are being used.


Four applications of antibiotics:

  1. Antibiotics have a wide use in medicine to fight infections.
  2. Certain antibiotics are used as food preservatives, specially fresh meat and fish.
  3. Some antibiotics are used in treating animal feed to prevent internal infection.
  4. Some antibiotics are used for controlling plant pathogens.

Question 8

List the merits of local defence system.


Merits of local defence system are:

  1. Local defence systems start working instantaneously.
  2. These systems are not dependent on previous exposure to infections.
  3. They are effective against a wide range of potentially infectious agents.

Question 9

Suppose a person develops the disease diphtheria. Comment upon the principle of the treatment he should receive.


Diphtheria is a serious bacterial infectious disease. It leads to cold, cough, sneeze, if left untreated in severe cases, it may lead to paralysis or heart failure.

Treatment includes a combination of medications and supportive care. The most important step is prompt intravenous administration of diphtheria toxoid which is made harmless. The harmless toxoid once administered in a patient's body triggers the production of antibodies against the pathogens causing diphtheria.

Question 10

Why is it important to know how the germs leave the body of a patient?


It important to know how the germs leave the body of a patient as there are some diseases and infections which are transmitted through air, water or just by direct contact. Therefore, to take precautions and protect others from further infections,it is must to know how the germs move out of the body of a patient.

Long Answer Type

Question 1

The principle of vaccination is to produce immunity against a disease. Explain.


  1. Vaccination is artificially introducing germs or its substances in the body in order to develop resistance to a particular disease.
  2. This practice is scientifically referred to as prophylaxis and the material being introduced into the body is called the vaccine.
  3. The vaccine or germ substance is introduced into the body usually by injection or orally sometimes.
  4. Inside the body, the vaccine stimulates lymphocytes to produce antibodies against the germs for that particular disease.
  5. Antibodies are an integral part of our immunity. Their function is to destroy the unwanted particles which enter the body.
  6. Vaccines give our immunity a signal to synthesize particular antibodies therefore the principal of vaccination is to provide immunity against a disease.

Question 2

"Abnormally, large number of WBCs in the blood are usually an indication of some infection in our body". Comment on the statement.


Whenever a germ or infection invades the body, the immune system receives a signal to synthesize particular antibodies. In response to the quantity of germ-multiplication in the body, white blood cells multiply rapidly which enables it to produce more antibodies thereby stopping the infection on time. Consequently, abnormal numbers of WBCs are an indication of some infection in the body.

Question 3

Explain briefly, the role of the following health aids:

(a) Antiseptics

(b) Disinfectants

(c) Vaccines


(a) Antiseptics — Antiseptics are mild chemical substance applied to the body to prevent its growth and kill germs. Example – Iodine and Lysol

(b) Disinfectants — These are the chemicals that kill microbes once they come in contact with them, they are too strong to be used on the body. Example – Phenol and Cresol

(c) Vaccines — They are the substances that are administered in the body to provide passive immunity. These are the materials that are germs or secreted by germs. Example – DTP, OPV