Aids to Health ICSE Class-9 Concise Biology Selina Solutions

Chapter-17 Aids to Health A Key To Healthy Life

Aids to Health ICSE Class-9 Concise Biology Selina Solutions Chapter-17 . We Provide Step by Step Answer of Progress Check , MCQs, Very Short Answer Type, Short Answer Type, Long Answer Type Questions of Exercise-17 Aids to Health A Key To Healthy Life. Visit official Website  CISCE  for detail information about ICSE Board Class-9.

Aids to Health Concise ICSE Class-9 Biology Selina Solutions Chapter-17 : A Key To Healthy Life

–: Select Topics :–

1_Progress Check (page-171),


2_Progress Check (page-172),

3_Progress Check (page-174),





Note :-  Before Viewing Concise Selina Solutions of Aids to Health Chapter-17 . Read the whole chapter carefully with figure. Focus on Aids to health: Active and passive immunity. meaning of active and passive immunity. 

An understanding of the use and action – vaccination , immunization , antitoxin, serum , antiseptics , disinfectants and antibiotic. Local defense system and its merits , difference between antiseptics and disinfectants in Aids To Health.

1_Progress Check (page-171), Concise Selina Solutions Aids to Health  A Key To Healthy Life

Question 1






Answer 1

(i) Saliva

(ii) sebum

(iii) mucus

Question 2









Answer 2



(iii)…False,- Human being has immune to a highly infectious disease of dogs.



(vi)…False,- a person once suffer from measles will not be suffer again

2_Progress Check (page-172), Selina Biology Solutions of Chapter-17, Aids to Health A Key To Healthy Life

Question 1


Answer 1

progress check page 174 chapter-17 Aids to Health selina Solutions

Question 2


Answer 2

1 Germ killing, 2 weakened germ, 3 poisonous germ. 4 Toxoids

Question 3





Answer 3



(iii)…Diphtheria, Tetanus

3_Progress Check (page-174), Concise Selina Biology Solutions 

Question 1









Answer 1

(i)……an disinfectant.

(ii)….is an antibiotic.

(iii)….can not apply on body.

(iv)…..are neither antiseptic nor disinfectant.

(v)….first antibiotic .

(vi)…..can be made synthetically


Question 2

List …..antibiotics

Answer 2

Antibiotics are used to treat or prevent some types of bacterial infection. They work by killing bacteria or preventing them from reproducing and spreading. Antibiotics aren’t effective against viral infections, such as the common cold, flu, most coughs and sore throats.

Revised Question 

A. MULTIPLE CHOICE TYPE Chapter: 17 – Aids to Health A Key To Healthy Life Concise 9th Biology Solution selina Publishers

Question 1

Select the most appropriate option in each case.

Penicillin is

(a) an antiseptic

(b) a disinfectant

(c) an antibiotic

(d) an anti-toxin

Answer 1

(c) An antibiotic

Question 2

‘T’ in DTP vaccination stands for

(a) Tuberculosis

(b) Typhoid

(c) Tetanus

(d) Tonsillitis

Answer 2

(c) Tetanus

Question 3

World Health Day is celebrated on

(a) April 7

(b) February 21

(c) October 10

(d) January 15

Answer 3

(a) April 7

Question 4

DPT stands for

(a) Diphtheria, Polio and Tetanus

(b) Diphtheria, Pertussis and Tetanus

(c) Dysentery, Polio and Typhoid

(d) Diphtheria, Polio and Typhoid

Answer 4

(b) Diphtheria, Pertussis and Tetanus

Question 5

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

Answer 5

(b) An extract of dead and weakened microbes

B. VERY SHORT ANSWER TYPE Chapter-17 A Key To Healthy Life Selina Concise ICSE Class-9 Biology Solutions

Question 1

Name the following:

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

(b) The antibiotic that was discovered first.

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

(d) Any four antiseptics, any two disinfectants and any two antibiotics.

(e) The vaccine that helps to produce immunity against polio.

Answer 1

(a) Arsphenamine or Salvarsan

(b) Penicillin

(c) Passive acquired immunity


 Antiseptics – Lysol, iodine, boric acid and carbolic acid

Disinfectants – Cresol and phenol

Antibiotics – Ampicillin and penicillin

(e) 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

Answer 2

(i) full forms of AIDS is Acquired Immuno Deficiency Syndrome

(ii) … BCG is Bacillus Calmette Guerin

(iii) …. DPT is Diphtheria, Pertussis and Tetanus vaccine

(iv) ….. WHO isWorld Health Organization

(v) …. HIV is Human Immunodeficiency Virus

(vi)…. . ATS is Anti Tetanus Serum

(vii) …TAB is Typhoid-Paratyphoid A and B

(viii) …STD is Sexually Transmitted Disease

Question 3

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

Answer 3

Antibodies are immunoglobulins which are produced in the blood to fight and destroy harmful microbes.

Selina Concise Biology Solutions of Chapter-17 Aids to Health C. 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.

Answer 1

(a) False. Lysol is an antiseptic.

(b) True

(c) False. Our body can make an unlimited variety of different antibodies.

(d) False. Salk’s vaccine is used against poliomyelitis.

(e) False. Treatment by the use of chemicals is known as chemotherapy.

(f) False. Selman Waksman coined the term ‘antibiotic’ for substances like penicillin.

(g) True.

(h) False. Vaccine provides the body with passive immunity.

(i) True.

(j) False. BCG is the vaccine given to babies to help build immunity against tuberculosis.

Question 2

Differentiate between:

(a) Antiseptic and antibiotic,

(b) Antiseptic and disinfectant,

(c) Disinfectant and deodorant,

(d) Vaccination and sterilisation,

(e) Active immunity and passive immunity,

(f) Innate immunity and acquired immunity

Answer 2

(a)Differentiate between Antiseptic and antibiotic
 Antiseptic is a mild chemical substance which is applied to the body to kill germs, whereas an antibiotic is a chemical substance produced by a microorganism which can kill or inhibit the growth of some other disease-producing microorganisms.
(b)  Differentiate between Antiseptic and disinfectant,

Antiseptic is a mild chemical substance which is applied to the body to kill germs, whereas a disinfectant is a strong chemical applied to spots or places on the body where germs thrive and multiply.

(c) Differentiate between Disinfectant and deodorant

 Disinfectant is a strong chemical applied to spots or places on the body where germs thrive and multiply, whereas deodorants are neither antiseptics nor disinfectants; they are aerosols used to mask a bad smell.

(d) Differentiate between Vaccination and sterilisation,

Vaccination is the introduction of any kind of dead or weakened germs into the body of a living being to develop immunity (resistance) against a disease, whereas sterilisation is a process of eliminating or killing all the microbes present on a surface, contained in a fluid, in medication or in a compound such as biological culture media.

(e) Differentiate between Active immunity and passive immunity

Active immunity is the immunity developed by an individual due to a previous infection or antigen which enters the body naturally, whereas passive immunity is the immunity provided to an individual from an outside source in the form of ‘readymade’ antibodies.

(f) Differentiate between Innate immunity and acquired immunity

 Innate immunity 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, whereas acquired immunity is the resistance to a disease which an individual acquires during a lifetime. It may be the result of either a previous infection or from ready made antibodies supplied from outside.

Question 3

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

Answer 3

(i) TAB vaccine for typhoid

(ii) BCG vaccine for measles

(iii) DTP vaccine for diphtheria, tetanus and whooping cough

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.

Vaccine Disease The
TAB 1. ___ 2. __
Salk’s vaccine 3. __ 4. __
BCG 5. __ Living
Vaccines for measles Measles 6. ___
Cowpox virus 7. __ 8. __
Toxoids 9. __ Extracts
of toxins
10. __ Secreted


Answer 4


Vaccine Disease(s) The
TAB 1.
Salk’s Vaccine 3.
. Killed
BCG 5.
Vaccines for Measles Measles 6.
Cowpox Virus 7.
Small pox
Toxoids 9.
of toxins


Question 5

Given below are the group  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).

Answer 5

(a) Lysol, benzoic acid, DDT, mercurochrome

Antiseptics. DDT is a wrong example for this category as it is a disinfectant which is not good for human skin.

(b) Formalin, iodine, Lysol, phenol

Disinfectants. Iodine is a wrong example as it is an antiseptic.


Vaccines. ATP is a wrong example as it is an energy carrier in the cells of all known organisms.

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

Germ-killing secretions. Skin is a wrong example as it is a protective mechanical barrier and prevents the entry of germs in our body.

Question 6

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

imunity table for Chapter-17 Selina Biology Solutions

Answer 6

(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.

Answer 7

  1. Antibiotics have a wide use in medicine to fight infections.
  2. Certain antibiotics are used as food preservatives, especially for 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 systems.

Answer 8

Merits of local defence systems:

  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.

Answer 9

Diphtheria is a serious bacterial infectious disease. It leads to cold, coughing, sneezing and, in severe cases if undiagnosed, it might result in heart failure or paralysis.

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.

Selina Biology Solutions D. LONG ANSWER TYPE Chapter-17 Aids to Health

Question 1

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

Answer 1

Vaccination is the practice of artificially introducing germs or the germ substance into the body for developing resistance to particular diseases.

Scientifically, this practice is called prophylaxis and the material introduced into the body is called the vaccine.

The vaccine or germ substance is introduced into the body usually by injection and sometimes orally (e.g. polio drops).

Inside the body, the vaccine stimulates lymphocytes to produce antibodies against the germs for that particular disease.

Antibodies are an integral part of our immunity. Their function is to destroy the unwanted particles which enter the body.

Vaccines give our immunity a signal to produce specific antibodies. Hence, the principle of vaccination is to produce immunity against a disease.

Question 2

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

Answer 2

Whenever a germ or infection invades the body, a signal is sent to the immune system to produce specific antibodies. To cope with the number of germs being multiplied inside the body, white blood cells start multiplying rapidly. This enables them to produce more number of antibodies and stop the infection in time. So, abnormally large numbers of WBCs in the blood are usually an indication of some infection in our body.

Question 3

Explain briefly, the role of the following health aids:

(a) Antiseptics

(b) Disinfectants

(c) Vaccines

Answer 3

(a) Antiseptics:

Antiseptics are mild chemical substances applied to the body which prevent the growth of some bacteria and destroy others.  

Examples: Lysol and iodine

(b) Disinfectants:

The Disinfectants are chemicals which kill microorganisms they come in contact with. These Disinfectants are usually too strong to be used on the body.

Examples: Cresol and phenol

(c) Vaccines:

Vaccines are materials administered in the body to provide passive immunity. The materials are generally germs or substances secreted by germs.

Examples: OPV (oral polio vaccine) and DTP (diphtheria, tetanus and pertussis)

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