Aids to Health

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

Answer

1. Sweat
2. Mucus
3. Skin (Keratin layer)

Mention if the following statements are True or False

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 foetus through placenta.
6. A person having once suffered from measles usually gets repeated attacks.

Answer

1. True
2. False
   Corrected Statement— Antibodies react with germs.
3. False
   Corrected Statement— Human beings do not suffer from all those diseases which attack dogs.
4. True
5. True
6. False
   Corrected Statement— A person having once suffered from measles usually do not gets repeated attacks (due to immunity as a result of previous infection).

Define the term prophylaxis.

Answer

Prophylaxis refers to the preventive or protective measures taken to prevent the occurrence or spread of a disease. It involves the use of various interventions, such as vaccines, medications, hygiene practices, lifestyle changes, or other strategies, to reduce the risk of developing a particular illness or to minimize its impact.

Name the four categories of materials used for preparing vaccine.

Answer

1. Killed germs
2. Living weakened germs
3. Living fully poisonous germs
4. Toxoids

Name the diseases prevented by:

1. Salk's vaccine
2. BCG vaccine
3. DPT vaccine

Answer

1. Poliomyelitis
2. Tuberculosis
3. Diphtheria, Pertussis, Tetanus

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 disinfectant.
5. Alexander Fleming discovered the first sulphonamide.
6. Antibiotics cannot be made synthetically.
7. Sulphonamides are now rarely used.

Answer

1. DDT is a disinfectant.
2. Penicillin is an antibiotic.
3. Disinfectants are applied on the places where germs thrive.
4. Deodorants are neither antiseptic nor disinfectant.
5. Alexander Fleming discovered the first antibiotic.
6. Antibiotics can be made synthetically.
7. Sulphonamides are now rarely used.

List any three uses of antibiotics.

Answer

Three uses of antibiotics are:

1. To fight infections
2. As food preservatives
3. Treating animal feed

Penicillin is

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

Answer

an antibiotic

Reason — Penicillin is an antibiotic which was first extracted from Penicillium notatum.
Antiseptics are chemicals applied on living tissues (like skin or wounds) to kill or prevent microbes. Penicillin is not used directly on skin; it works inside the body, so it is not an antiseptic. Disinfectants are chemicals used on non-living objects (floors, instruments, surfaces) to kill germs. Penicillin is not used for cleaning objects, so it is not a disinfectant. Antitoxins are substances that neutralize toxins produced by bacteria. Penicillin does not neutralize toxins; it kills bacteria, so it is not an antitoxin.

Which of the following immunity is present from our birth?

1. Innate immunity
2. Active immunity
3. Passive immunity
4. Acquired immunity

Answer

Innate immunity

Reason — Innate immunity is the inborn or natural immunity present in the body.
Active immunity develops after exposure to a pathogen or vaccine. It is not present at birth. Passive immunity is obtained when antibodies are transferred from another source (e.g., mother to baby through placenta or milk). It is not permanent and not fully “present from birth” as a system. Acquired immunity develops during life after infection or vaccination, so it is not present at birth.

Naturally acquired active immunity would be most likely acquired through which of the following processes?

1. Vaccination
2. Drinking colostrum
3. Natural birth
4. Previous infection with a disease-causing organism

Answer

Previous infection with a disease-causing organism

Reason — In case of infection in the body, there is formation of antibodies to fight the infection. These antibodies remain in the body for few years providing naturally acquired active immunity.
Vaccination gives artificially acquired active immunity, not natural immunity, because it is induced by medical intervention. Colostrum provides passive immunity, where ready-made antibodies are transferred from mother to baby. It is not active immunity because the body does not produce its own antibodies. Natural birth itself does not provide immunity. Although some maternal antibodies may be transferred before birth, this is still passive immunity, not active immunity.

DPT stands for:

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

Answer

Diphtheria, Pertussis and Tetanus

Reason — DPT is the vaccine of these three diseases-Diphtheria, Pertussis and Tetanus.
Polio is not part of DPT; it is given in a separate vaccine (like OPV/IPV). Dysentery, Polio and Typhoid are not included in the DPT vaccine combination.

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

Answer

An extract of dead and weakened microbes.

Reason — Vaccines are an extract of dead and weakened microbes which when injected into the body lead to formation of corresponding antibody.
Some vaccines may target toxoids, but vaccines are not generally extracts of toxins. Vaccines are not chemical extracts from fungi. Some antibiotics come from fungi, but vaccines are biological preparations. Chemicals that are applied on the skin to kill bacteria are antiseptics, not vaccines. They act externally and do not provide immunity.

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

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

Answer

Bacillus

Reason — BCG stands for Bacillus of Calmette and Guerin.
Beri-beri is a vitamin deficiency disease caused by lack of vitamin B1. While BCG is related to bacteria, the correct word in the name is specifically “Bacillus,” not the general term bacteria.

The body's defense against diseases is termed as:

1. Hygiene
2. Immunity
3. Health
4. None of these

Answer

Immunity

Reason — Immunity is the ability of body to fight infections.
Hygiene refers to clean habits and practices that help prevent diseases, but it is not the body’s internal defense system. Health means a state of physical and mental well-being, not the defense mechanism itself.

The slimy secretion of the epithelial lining of the various organs is called:

1. Antiseptic
2. Antibodies
3. Both (i) & (ii)
4. Mucus

Answer

Mucus

Reason — The slimy secretion of the epithelial lining of the various organs is called mucus. It traps bacteria.
Antiseptics are chemical substances used to kill or prevent the growth of microorganisms on living tissues, not natural body secretions. Antibodies are proteins produced by the immune system to fight pathogens, not slimy secretions from epithelial cells.

Which of the following is not a germ-killing secretion?

1. Blood
2. Saliva
3. Tears
4. Sweat

Answer

Blood

Reason — Blood is not a germ-killing secretion. Its main functions are transporting oxygen, nutrients, hormones, and waste materials.
Saliva contains enzymes like lysozyme that help kill or inhibit bacteria in the mouth. Tears contain lysozyme, which destroys bacteria and protects the eyes from infection. Sweat helps wash away microbes from the skin and contains substances that can inhibit bacterial growth.

Antibody is a blood serum protein produced in response to:

1. Antitoxins
2. Antibiotics
3. Antigens
4. Antiseptics

Answer

Antigens

Reason — Antibody is formed in our body in response to foreign antigen.
Antitoxins are substances that neutralize toxins, but they are not the trigger for antibody production. In fact, some antitoxins are themselves types of antibodies. Antibiotics are medicines used to kill bacteria. They do not trigger antibody production in the immune system. Antiseptics are chemicals used externally to kill microbes. They do not enter the body’s immune system to stimulate antibody production.

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 ?

1. Prerna and Shreya
2. Shreya and Rahul
3. Rahul and Rishi
4. Rishi and Prerna

Answer

Rahul and Rishi

Reason — Mercurochrome is used on cuts and wounds as an antiseptic. Carbolic acid is used as early antiseptic (used with caution).
Boric acid is used as an antiseptic for eyes and wounds. Benzoic acid is used as a mild antiseptic and food preservative.

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) The medicines made by the combination of penicillin and sulpha drugs.

(e) The scientist who discovered the first antibiotic.

Answer

(a) Salvarsan

(b) Penicillin

(c) Passive acquired immunity

(d) Pentidsulph

(e) Alexander Fleming

Write the full forms of the following abbreviations:

(a) AIDS

(b) BCG

(c) DPT

(d) DDT

(e) WHO

(f) HIV

(g) STD

(h) WBC

(i) TAB

(j) COVID-19

Answer

(a) AIDS — Acquired Immuno Deficiency Syndrome

(b) BCG — Bacillus Calmette Guerin

(c) DPT — Diphtheria Pertussis and Tetanus vaccine

(d) DDT — Dichloro Diphenyle Trichloro-ethane

(e) WHO — World Health Organization

(f) HIV — Human Immunodeficiency Virus

(g) STD — Sexually Transmitted Disease

(h) WBC — White Blood Cell

(i) TAB — Typhoid Paratyphoid A & B

(j) COVID-19 — Corona Virus Disease 2019

Name:

(a) Five antiseptics

(b) Five disinfectants

(c) Two antibiotics

(d) Two sulpha drugs

(e) Two sexually transmitted diseases

Answer

(a) Lysol, Carbolic acid, Iodine, Benzoic acid and Boric acid.

(b) Cresol, Phenol, Lysol, Lime and 40% Formalin.

(c) Penicillin and Streptomycin.

(d) Sulphadiazine and Sulphanilamide.

(e) Gonorrhea and Syphilis.

Define the terms:

(a) Immunity

(b) Antibodies

(c) Prophylaxis

(d) Vaccine

(e) Immunisation

Answer

(a) Immunity is the resistance to the onset of a disease after infection by harmful germs.

(b) Antibodies are special types of proteins that are present in our body or are formed in response to any infection or toxin.

(c) Prophylaxis is the prevention of disease through vaccines, medications, hygiene practices, lifestyle changes, and other strategies to reduce the risk and impact of illness.

(d) Vaccine is a biological formulation that consist of dead or weakened disease causing organism that provides active acquired immunity to a particular infectious disease.

(e) Developing resistance to disease-producing germs or their toxins by introducing killed germs or germ substances to induce the production of specific antibodies.

Correct the following statements by changing the first/last word only:

(a) Lysol is an antibiotic.

(b) The treatment of diseases by the use of chemical substances is known as allopathy.

(c) RBCs are germ-fighting cells of our body.

(d) Antiseptics are the proteins that belong to the class of immunoglobulins.

(e) BCG vaccines are given to small babies orally.

Answer

(a) Lysol is an antiseptic.

(b) The treatment of diseases by the use of chemical substances is known as chemotherapy.

(c) WBCs are germ-fighting cells of our body.

(d) Antibodies are the proteins that belong to the class of immunoglobulins.

(e) BCG vaccines are given to small babies intra-dermal.

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.

Answer

Choose the odd one out and write the category for the remaining terms.

(a) Carbolic acid, Formalin, Benzoic acid, Boric acid

(b) Mercurochrome, Cresol, Phenol, Bordeaux mixture

(c) ATP, DPT, BCG, TAB

(d) Saliva, Sweat, Skin, Tears

(e) Chloromycetin, Streptomyces, Streptomycin, Aureomycin

Answer

(a) Odd one out— Formalin (disinfectant)
Carbolic acid, Benzoic acid, Boric acid — antiseptic

(b) Odd one out— Mercurochrome (antiseptic)
Cresol, Phenol, Bordeaux mixture — disinfectant

(c) Odd one out— ATP (energy providing compound formed during respiration)
DPT, BCG, TAB — Vaccine

(d) Odd one out— Skin
Saliva, Sweat, Tears — germ killing secretions

(e) Odd one out— Streptomyces (bacterium)
Chloromycetin, Streptomycin, Aureomycin — antibiotics

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

Answer

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.

List the merits of local defence system.

Answer

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.

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

Answer

• 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

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

Answer

(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

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

Answer

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.

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

Answer

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.

Explain briefly, the role of the following health aids:

(a) Antiseptics

(b) Disinfectants

(c) Vaccines

Answer

(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

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

Answer

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.

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

Answer

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.

The figures A, B and C given below represent a kind of protective method in our body. Study the same and answer the following question:

(a) Name and define the process which occurs in figure A.

(b) What kind of blood vessel is shown in figure-A? Write its one specific structural feature.

(c) Name and define the process occurring in figure-B.

(d) What kind of blood cell is shown in the figures? Write its technical name also.

(e) Name the specific type of cell containing a 4 lobed nucleus of the category answered by you in part (d) above.

Answer

(a) The process is Diapedesis. It is defined as the squeezing of WBCs through the wall of capillaries into the tissues.

(b) Capillary wall. It is thin and semi-permeable.

(c) The process is Phagocytosis. It is the process in which WBCs engulf particle-like solid substances, especially bacteria.

(d) White Blood Cell (WBC), Leucocyte.

(e) Neutrophil.

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 ?

(b) Name the scientist who discovered the first antibiotic.

(c) Write the scientific name of the source from which the first antibiotic was produced.

(d) Give two examples of antibiotics.

(e) Mention one use of the above mentioned antibiotic other than in medical treatment.

*Answer

(a) The two kinds of microbes used to prepare antibiotics are fungi and bacteria.

(b) Alexander Fleming discovered the first antibiotic, penicillin.

(c) The first antibiotic, penicillin, was obtained from the fungus Penicillium notatum.

(d) Two examples of antibiotics are Penicillin and Streptomycin.

(e) Antibiotics are also used in animal husbandry and poultry farming to prevent and control bacterial infections in livestock.

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.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is True and R is False.

Reason — A is True as immunity refers to the body’s ability to resist or fight off infections caused by harmful pathogens. It can be natural or acquired and may result from previous infection or vaccination.
R is False as antigens are foreign substances (such as bacteria or viruses) that trigger the immune response. Antiseptics are chemical substances used externally to kill germs on skin or surfaces, they are not part of the immune system. The proteinaceous substances involved in immunity are antibodies, not antigens or antiseptics.

Therefore, A is True and R is False is the correct option.

Assertion (A):

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.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is true but R is false.

Reason — A is true as the BCG vaccine (Bacillus Calmette–Guérin) for tuberculosis is made from live, weakened Mycobacterium bacteria. These germs are non poisonous and do not cause disease but stimulate an immune response.
R is false as living, weakened germs used in the BCG vaccine are effective in providing protection, especially in children.

Therefore, A is true but R is false is the correct option.

Assertion (A): Active immunity is produced by one's own body.

Reason (R): Active immunity is induced by infection or by contact with immunogens.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true and R is the correct explanation of A.

Reason — A is true as active immunity involves the body’s own immune system producing antibodies in response to an infection or vaccine. It provides long-lasting protection.
R is true as immunogens (like parts of bacteria or viruses) stimulate the immune system to produce a response. This can happen through natural infection or vaccination.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

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.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is True and R is False.

Reason — A is True as both antiseptics and disinfectants are used to kill or inhibit the growth of pathogenic microorganisms that can cause disease.
R is False as antiseptics are used on living tissues (like skin) to kill or inhibit microbes e.g. Dettol, iodine. Disinfectants are used on non-living surfaces (floors, instruments) and not inside the human body, as they can be too harsh or toxic.

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.

(b) Write the scientific name of the mould from which the first antibiotic was extracted.

(c) Write two more uses of antibiotics, other than being used in medicines.

(d) Besides moulds, which other category of organisms is widely used to obtain certain kinds of antibiotics ?

(e) Name the vaccine which can be used to preyent the bacterial disease - tuberculosis.

Answer

(a) The first antibiotic discovered was penicillin. It was discovered by Alexander Fleming.

(b) The first antibiotic penicillin was obtained from the mould Penicillium notatum.

(c) Two more uses of antibiotics, other than being used in medicines are:

1. Antibiotics are used in animal husbandry and poultry farming to prevent bacterial infections in livestock.

2. Antibiotics are used in food preservation to prevent spoilage by bacteria (in controlled conditions).

(d) Besides moulds, bacteria are also widely used to produce antibiotics.

(e) The vaccine used to prevent tuberculosis is the BCG vaccine.