Selina Solutions for Class 9 Biology Chapter 17 - AIDS to Health

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Access Answers of Biology Selina class 9 Chapter 17 – AIDS to Health

  1. Give one example of each of the following:

    1. Germ killing body secretion.
    2. Germ trapping body secretion
    3. Mechanical barrier that prevents the entry of germs into the body.

    Solution:

    1. Germ killing body secretion – saliva
    2. Germ trapping body secretion – Sebum
    3. Mechanical barrier that prevents the entry of germs into the body – Mucus
  2. Mention of the following statements are True(T) or false(F)

    1. Immune system deals with the germs after they have entered the body.
    2. Antibodies eat up the germs
    3. Human beings can suffer from all those diseases which attack dogs
    4. Anti-venin injection against snake bite is an example of artificially acquired passive immunity.
    5. Mother’s antibodies may reach the fetus through placenta
    6. A person having once suffered from measles usually gets repeated attacks.

    Solution:

    1. The statement is true.
    2. The statement is true.
    3. The statement is false. Human beings are immune to a highly infectious disease of Dogs.
    4. The statement is true.
    5. The statement is true.
    6. The statement is false. A person having once suffered from measles will not normally suffer from it again.
  3. Define the term prophylaxis.

    Solution:

    Artificially introducing the germs or the germ substance into the body for developing resistance to a particular disease. Scientifically this process is referred to as prophylaxis.

  4. Name the four categories of materials used for preparing vaccines

    Solution:

    The four categories of vaccines are:

    • Killed germs
    • Living weakened germs
    • Living fully poisonous germs
    • Toxoids
  5. Name the diseases prevented by:

    1. Salk’s vaccine
    2. BCG vaccine
    3. DTP vaccine

    Solution:

    1. Salk’s vaccine – Poliomyelitis
    2. BCG vaccine – Tuberculosis
    3. DTP vaccine – Pertussis(whooping cough), diphtheria, tetanus
  6. Correct the following statements if they are false (without changing the first word).

    1. DDT is an antiseptic.
    2. Penicillin is a disinfectant.
    3. Disinfectants are applied on the body
    4. Deodorants are both antiseptic as well as disinfectants
    5. Alexander Fleming discovered the first sulphonamide
    6. Antibiotics cannot be made synthetically
    7. Sulphonamides are now rarely used.

    Solution:

    1. DDT is a disinfectant.
    2. Penicillin is an antibiotic.
    3. Disinfectants cannot be applied on the body
    4. Deodorants are neither antiseptics nor disinfectants.
    5. Alexander Fleming discovered the first antibiotic
    6. Antibiotics can be made synthetically
    7. Sulphonamides are now rarely used.
  7. List any three uses of antibiotics.

    Solution:

    The three uses of antibiotics are:

    • They are used to fight infections
    • Certain antibiotics are used as food preservatives, especially fresh meat and fish.
    • Some are used to control plant pathogens

Multiple Choice Type

(Select the most appropriate option in each case)

  1. Penicillin is

    1. An antiseptic
    2. A disinfectant
    3. An antibiotic
    4. An anti-toxin

    Solution:

    (c) An antibiotic

    It was the first antibiotic discovered by Alexander Fleming.

  2. “T” in DTP vaccination stands for

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

    Solution:

    (c) Tetanus

    DTP stands for Diphtheria, Tetanus and Pertussis

  3. World Healthy Day is celebrated on

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

    Solution:

    (a) April 7

    It is celebrated to create consciousness about keeping oneself healthy and to disseminate the message at all levels.

  4. DTP stands for

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

    Solution:

    (b) Diphtheria, Pertussis and Tetanus

    DTP it is a vaccination used the treat Pertussis, Diphtheria and Tetanus

  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.

    Solution:

    (b)An extract of dead and weakened microbes

    The material introduced into the body during the practice of prophylaxis is known as vaccine

Very short answer type

  1. Name the following:

    1. The drug based on arsenic compound, produced in 1910 which killed germs of syphilis.
    2. The antibiotic that was discovered first.
    3. The category of immunity required in the treatment of snake-bite.
    4. Any four antiseptics, any two disinfectants and any two antibiotics.
    5. The vaccines that help to produce immunity against Polio.

    Solution:

    1. The drug based on arsenic compound, produced in 1910 which killed germs of syphilis – Salvarsan and Arsphenamine
    2. The antibiotic that was discovered first – Penicillin
    3. The category of immunity required in the treatment of snake-bite – Passive acquired immunity
    4. Any four antiseptics, any two disinfectants and any two antibiotics.

      Antiseptics

      Carbolic acid, Lysol, Boric acid, Iodine

      Disinfectants

      Cresol, phenol

      Antibiotics

      Penicillin, Ampicillin

    5. The vaccines that help to produce immunity against Polio – OPV – Oral polio vaccine
  2. Write the full forms of:

    1. AIDS
    2. BCG
    3. DPT vaccine
    4. WHO
    5. HIV
    6. ATS
    7. TAB
    8. STD

    Solution:

    1. AIDS – Acquired Immuno Deficiency Syndrome
    2. BCG – Bacillus Calmette Guerin
    3. DPT vaccine – Diphtheria Pertussis and Tetanus vaccine
    4. WHO – World Health Organization
    5. HIV – Human Immunodeficiency virus
    6. ATS – Anti Tetanus Serum
    7. TAB – Typhoid Paratyphoid A & B
    8. STD – Sexually Transmitted Disease
  3. Give the technical term for the kind of proteins produced in the blood to fight and destroy harmful microbes

    Solution:

    Antibodies. They are the immunoglobulin that are produced in the blood to fight and destroy harmful microbes.

Short Answer Type

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

    1. Lysol is an antibiotic.
    2. Sweat and tears contain germs-killing substances.
    3. Our body can make only a limited variety of different antibodies
    4. Salk vaccine is used against tuberculosis
    5. Treatment by the use of chemicals is known as allopathy
    6. Alexander Fleming coined the term “antibiotic” for substances like penicillin.
    7. DDT is a disinfectant.
    8. Vaccine provides the body with Active Immunity
    9. Penicillin was discovered by Alexander Fleming.
    10. BCG is the vaccine given to babies to help build immunity against three common diseases.

    Solution:

    1. The statement is false. Lysol is an antiseptic
    2. The statement is true.
    3. The statement is false. Our body can make an unlimited variety of different antibodies
    4. The statement is false. Salk vaccine is used against Poliomyelitis.
    5. The statement is false. Use of chemicals to treat is known as chemotherapy
    6. The statement is false. The term was coined by Selman Waksman.
    7. The statement is true.
    8. The statement is false. It provides the body with Passive Immunity.
    9. The statement is true.
    10. The statement is false. BCG is used to treat Tuberculosis.
  2. Differentiate between:

    1. Antiseptic and antibiotic
    2. Antiseptic and disinfectant
    3. Disinfectant and deodorant
    4. Vaccination and sterilization
    5. Active Immunity and passive immunity
    6. Innate immunity and acquired immunity

    Solution:

    The differences are as follows:

    a)Antiseptic and antibiotic

    Antiseptic

    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

    Antiseptic

    Disinfectant

    It is a mild chemical substance applied to the body to kill germs

    It is a strong chemical applied to spots on the body where germs live and multiply

    c) Disinfectant and deodorant

    Disinfectant

    Deodorant

    It is a strong chemical applied to spots on the body where germs live and multiply

    They are neither antiseptics nor disinfectants. They are used to mask bad smell and are aerosols.

    d) Vaccination and sterilization

    Vaccination

    Sterilization

    It is the introduction of any kind of weakened/dead germs into the body of a living beings to develop resistance against 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 Immunity

    Passive 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 Immunity

    Acquired Immunity

    It is the immunity by virtue of genetic constitutional makeup

    It is the resistance to a disease the body acquires in his lifetime.

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

    Solution:

    Three vaccines and the diseases for which they provide immunity are as follows:

    Name of the Vaccine

    Disease for which immunity provided

    TAB

    Typhoid

    Salk’s vaccine

    Poliomyelitis

    BCG

    Tuberculosis

  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(s)

    The nature of vaccine

    TAB

    1. __________
    1. __________

    Salk’s vaccine

    1. __________
    1. __________

    BCG

    1. __________

    Living weakened germs

    Vaccine for measles

    Measles

    1. __________

    Cowpox virus

    1. __________
    1. __________

    Toxoids

    1. __________

    Extracts of toxins

    Secreted by bacteria

    Solution:

    Vaccine

    Disease(s)

    The nature of vaccine

    TAB

    1. Typhoid
    1. Killed germs

    Salk’s vaccine

    1. Poliomyelitis
    1. Killed germs

    BCG

    1. Tuberculosis

    Living weakened germs

    Vaccine for measles

    Measles

    1. Living weakened germs

    Cowpox virus

    1. Small pox
    1. Living fully poisonous germs

    Toxoids

    1. Diphtheria

    Extracts of toxins

    1. Tetanus

    Secreted by bacteria

  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.

    1. Lysol, benzoic acid, DDT, mercurochrome.
    2. Formalin, Iodine, Lysol, Phenol
    3. BCG, DTP, ATP.
    4. Tears, Skin, Nasal Secretion, HCl (in stomach)

    Solution:

    1. Lysol, benzoic acid, DDT, mercurochrome – DDT is a wrong example as all others are antiseptics and DDT is a disinfectant which cannot be applied on the skin.
    2. Formalin, Iodine, Lysol, Phenol – Iodine is a wrong example as all others are disinfectant where Iodine is an antiseptic
    3. BCG, DTP, ATP – ATP is a wrong example as all others are vaccines whereas ATP carries energy in living cells.
    4. Tears, Skin, Nasal Secretion, HCl (in stomach) – skin is a wrong example as all others are germ-killing secretions whereas skin is a protect mechanical barrier, preventing germ-entry.
  6. Given below is a scheme of classifying immunity against human diseases. Fill up the types of immunity in the blanks 1-9.

    Selina Concise Biology Class 9 Chapter 17 Solutions-1

    Solution:

    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

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

    Solution:

    Listed below are the four applications of antibiotics:

    • They are widely used to fight infections
    • They are used as food preservatives especially in fish and fresh meat
    • Used in treating animal feed to prevent internal infections
    • Used for controlling plant pathogens
  8. List the merits of local defence system.

    Solution:

    Merits of the local defence system are as follows:

    • They instantaneously start working
    • They are not dependent on previous exposure to infections
    • Are effective against a wide range of potentially infectious agents.
  9. Suppose a person develops the disease diphtheria. Comment upon the principle of the treatment he should receive.

    Solution:

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

    Treatment for Diphtheria:

    • Combination of supportive care and medication
    • Prompt intravenous administration of diphtheria toxoid which is made harmless
    • Once this is administered into the body of the patient, it stimulates antibody production against pathogens that cause diphtheria

Long Answer Type

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

    Solution:

    Vaccination is artificially introducing germs or its substances in the body in order to develop resistance to a particular disease. This practice, scientifically referred to as prophylaxis and the material being introduced is the vaccine. Vaccines are generally introduced by injection or orally sometimes.

    Once the vaccine enters the body, it triggers the lymphocytes to synthesize antibodies to fight germs for that specific disease. Vaccines provide our immunity a signal to synthesize particular antibodies therefore the principal of vaccination is to provide immunity against a disease.

  2. “Abnormally, large number of WBC’s in the blood are usually an indication of some infection in our body”. Comment on the statement.

    Solution:

    Whenever there is an infection in 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 in infection on time. Consequently, abnormal numbers of WBCs are an indication of some infection in the body.

  3. Explain briefly, the role of the following health aids:

    1. Antiseptics
    2. Disinfectants
    3. Vaccines

    a)Antiseptics –

    It is a mild chemical substance applied to the body to prevent its growth and kill germs.

    Example – Iodine and Lysol

    b)Disinfectant

    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

Selina Solutions for class 9 Biology Chapter 17 – AIDS to Health

ICSE Class 9 Biology Chapter 17 – AIDS to health chapter is classified under Unit – VI of Biology textbook – Health & Hygiene. Health refers to the normal and healthy state of the body in all the three aspects namely – physical, mental and social wellness while Hygiene concerns with the conditions and practices in order to maintain health and prevent any chance of diseases.

The unit AIDS to health is included in the syllabus for class 9 in order for students to familiarise with various (natural and artificial) ways to protect oneself from diseases. Apart from the importance of the topic for examination, the information provided is very essential and required to lead a healthy life.

Concept of health is discussed at the personal and community level. Immunity is the body’s defence against diseases. The concept is discussed along with the way in which the disease can enter the body. Some other concepts that are discussed are:

  • Local defence system
  • Immune system
  • Types of immunity
  • Antibodies
  • Vaccination and immunization

The chapter covers the following types of questions:

  • Multiple-choice questions
  • State whether true/false
  • Fill ups
  • Very short answer type questions
  • Short answer type questions
  • Long answer type questions

List of subtopics covered in Chapter 17 – AIDS to Health

Number

Subtopic

17.1

Need to keep healthy

17.2

Immunity

17.2.1

Local defence system

17.2.2

Immune system

17.2.3

Antibodies

17.3

Vaccination and Immunisation

17.4

Antitoxins

17.5

Antiseptics and disinfectants prevent catching diseases

17.5.1

Antiseptics

17.5.2

Disinfectants

17.6

Antibiotics – Penicillin and others

17.7

Sulphonamide group of medicines

List of Exercise

Name of the exercise

Number of questions

Question Type

Page number

Progress Check

7

short

171,172,174

Review questions

5

MCQ

174

12

short

174, 175

3

long

175

Selina Solutions for class 9 Biology Chapter 17 – AIDS to Health

Health is an important aspect of life that is often ignored. Through this chapter, students are enlightened with the basic concept of immunity. It is the basic defence system of the body that counter attacks if there is an entrance of any foreign particle in the body. The defence system of the body works at two levels:

  • Local defence system
  • Immune system

The immune system provides resistance to the onset of disease after infection by harmful germs. There are different types of immunity, and further sub-categories under each of these:

  • Innate immunity
  • Acquired immunity

Through this chapter, the readers are also guided about the concepts of antibiotics, antiseptics, disinfectants and their sources and the various ways through which diseases can be treated and prevented by the use of these.

Key Features of Selina Solutions for class 9 Biology Chapter 17 – AIDS to Health

  • Easy to understand and helpful study tool
  • Detailed and step by step organization of answers
  • Solutions are answered using the simplest language and easy terminologies
  • Selina solutions are easily accessible
  • Explanation provided for the activity – State whether statements are true or false
  • Use of pointers wherever necessary

Frequently Asked Questions on AIDS to Health

What is prophylaxis?

Artificially introducing the germs or the germ substance into the body for developing resistance to a particular disease. Scientifically this process is referred to as prophylaxis.

Name the four categories of materials used for preparing vaccines?

The four categories of vaccines are:

  • Killed germs
  • Living weakened germs
  • Living fully poisonous germs
  • Toxoids

List any three uses of antibiotics?

The three uses of antibiotics are:

  • They are used to fight infections
  • Certain antibiotics are used as food preservatives, especially fresh meat and fish.
  • Some are used to control plant pathogens

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

Antibodies. They are the immunoglobulin that are produced in the blood to fight and destroy harmful microbes.

What are the merits of local defence system?

Merits of the local defence system are as follows:

  • They instantaneously start working
  • They are not dependent on previous exposure to infections
  • Are effective against a wide range of potentially infectious agents.

Explain Antiseptics?

It is a mild chemical substance applied to the body to prevent its growth and kill germs.
Example – Iodine and Lysol

What is 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