WBBSE Solutions For Class 9 Life Science And Environment Chapter 4 Immunity And Human Diseases

Chapter 4 Biology And Human Welfare Summary

1. The ability of the host to fight and protect against disease-causing organisms conferred by the immune system is called immunity.
2. Immunity is of two types:
   1. Innate Immunity
   2. Acquired Immunity.
3. Innate immunity is a non-specific type of immunity in an individual that is present at the time of birth. It works by preventing the entry of pathogens through various barriers.
4. There are various types of barriers such as physical barriers (skin), and chemical barriers (lysozyme), by which the body prevents the entry of foreign agents into our body.
5. Acquired immunity is pathogen-specific and is characterized by a memory of the activities of a pathogen in the body of a living organism.
6. When the pathogen is encountered for the first time a primary response of low intensity is produced.
7. Subsequent encounters with the same pathogen produce a high-intensity response of high intensity with the help of memory cells.
8. This is called secondary or anamnestic response.
9. Primary and secondary responses are carried out with the help of 2 special types of lymphocytes-B lymphocytes and T lymphocytes.
10. B lymphocytes produce special proteins called antibodies whereas the T lymphocytes help B lymphocytes to produce antibodies.
11. Each antibody has 2 light chains and 2 heavy chains.
12. It is represented as H₂L₂.
13. Antibodies in our bodies are of different types such as IgG, IgA, IgD, IgE, and IgM.
14. The antigen is a substance usually protein in nature (sometimes polysaccharide or lipid) that generates a specific immune response and induces the formation of specific antibodies or specially sensitized T cells or both.
15. There are different types of antigens on the basis of antigen:
    1. Exogenous antigens are the foreign particles that enter the body system from outside, start circulating in body fluids, and are phagocytosed by antigen-processing cells.
    2. Endogenous antigens are the antigenic products, subfragments or any compounds that are produced by the body itself.
16. An immune response is a reaction that occurs within an organism for the purpose of defending against foreign invaders.
17. The humoral immune response is a kind of immune response that is involved in the production of antibodies.
18. These antibodies are present in the blood.
19. Cell-mediated immunity is an immune response that does not involve antibodies but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
20. The body is able to differentiate between ‘self and ‘non-self’ and the cell-mediated immune response is responsible for the graft rejection.
21. When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body.
22. This type of immunity is called active immunity.
23. Examples: vaccines like BCG, and MMR.
24. When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity. Examples-Anti-tetanus injection, and injections for snake bites.
25. Vaccination is the introduction of antigenic proteins of pathogens or part or whole of inactivated or weakened pathogens into the host body so as to trigger the host immune system to produce antibodies against the antigens.
26. Vaccines are products that produce immunity to a specific disease.
27. There are different types of vaccines i.e:
    1. live attenuated (LAV): BCG, OPV,
    2. Inactivated (killed antigen): IPV,
    3. Subunit (purified antigen): Hepatitis B
    4. Toxoid (inactivated toxins): Tetanus Toxoid.
28. The disease is the stage when the body or any part of it shows some disturbance in normal functions.
29. Pathogen refers to any disease-causing organism.
30. Infection refers to the pathological state resuming from the invasion of the body by pathogenic microorganisms, Incubation period refers to the period bothers exposure to an infection and the appearance of the first symptoms.
31. Communicable diseases are diseases that are spread by different organisms such as bacteria, viruses, and fungi.
32. These are transmitted from one person to another.
33. Examples: Flu, malaria, syphilis.
34. Non-communicable diseases are not transmitted from one person to another.
35. These are different types of allergies, nutritional deficiencies, etc.
36. Diarrhea is caused by protozoa, bacteria or viruses. It is contaminated by food and water.
37. Malaria is caused by Plasmodium (Protozoa) due to the bite of female Anopheles.
38. Diphtheria is caused by Corynebacterium diphtheria.
39. Pneumonia is caused by Streptococcus pneumonia (bacterial).
40. It is transmitted by cough, sneeze droplets.
41. Tuberculosis is caused by Mycobacterium tuberculosis transmitted through cough/sneeze droplets.
42. Tetanus is caused by Clostridium tetani (bacteria).
43. It mainly affects the muscle and the nervous system.
44. Dengue is caused by Flavivirus.
45. The Aedes aegypti mosquito is the vector of this disease.
46. Hepatitis A is water borne disease.
47. It is caused by the Hepatitis A virus.
48. Hepatitis B is transmitted by blood transfusion, sexual contact, mother to baby by pregnancy or nursing.
49. HIV causes AIDS and interferes with the body’s ability to fight infections.
50. The virus can be transmitted through contact with infected blood, semen or vaginal fluid.
51. Washing is a method of cleaning usually with water and often some kind of soap or detergent.
52. It may be practiced for personal hygiene, religious rituals or therapeutic purposes.Read and Learn More WBBSE Solutions for Class 9 Life Science and Environment

 

Chapter 4 Biology And Human Welfare Immunity And Human Diseases Short Answer Type Questions

Question 1 What is immunology?

Answer:

Immunology:-

The branch of science, that deals with the study of antigens, antibodies, and the overall immune system of the body, is known as immunology.

WBBSE Class 9 Life Science Solutions

Question 2 What is immunity?

Answer:

Immunity:-

Immunity is defined as the defense mechanism of the body against a specific infection or toxin or any harmful foreign material, entering the body by the action of specific antibodies or specialized cells or agents.

Question 3 What is meant by innate immunity?

Answer:

Innate Immunity:-

Innate immunity refers to non-specific defense mechanisms that come into play immediately or within hours of an antigen’s appearance in the body.

Question 4 What is meant by acquired immunity?

Answer:

Acquired Immunity:-

The immunity, which develops within the body of an organism by any infection, vaccination, or by the introduction of antibodies artificially, is called acquired immunity.

Question 5 Schematically represent different types of acquired immunity

Answer:

Different Types Of Acquired Immunity Are Given Below:-

A schematic representation of different types of acquired immunity is given below

Question 6 What is meant by active acquired immunity?

Answer:

Active Acquired Immunity:-

The immunity, which is developed in the body of an organism by the introduction of an antigen, naturally or artificially, is called active acquired immunity.

WBBSE Class 9 Life Science Solutions

Question 7 What is artificial active immunity?

Answer:

Artificial Active Immunity:-

The active immunity, which develops in an organism after vaccination is called artificial active immunity.

Examples: Vaccines like DPT, OPV, BCG, etc. develop artificial active immunity.

Question 8 What is passive acquired immunity?

Answer:

Passive Acquired Immunity:-

The immunity which is developed in the body of an organism by the introduction of an antibody, naturally or artificially, is called passive acquired immunity.

Question 9 What is natural active immunity?

Answer:

Natural Active Immunity:-

Active immunity, which is developed in an organism after natural infection by any pathogen (virus, bacteria, etc.) is known as natural active immunity.

Example: After infection with chicken pox, a person develops natural active immunity against this disease and is not attacked by the same disease in the future.

Question 10 What is natural passive immunity?

Answer:

Natural Passive Immunity:-

Passive immunity, which is developed by the inflow of antibodies from the mother to the fetus through placental circulation is known as natural passive immunity.

Example: Immunoglobulin A, acquired by a baby through the colostrum of breast milk of the mother, develops natural passive immunity.

Question 11 What is artificial passive immunity?

Answer:

Artificial Passive Immunity:-

Passive immunity, which develops in an animal through the introduction of antibodies from outside by injection, is known as artificial passive immunity.

Example: Antitoxin serum, produced from horse blood, is injected to save the life of a person suffering from a snake bite.

WBBSE Class 9 Life Science Solutions

Question 12. Distinguish between innate and acquired immunity.

Answer:

Differences between innate and acquired immunity:

Question 13. Distinguish between active acquired immunity and passive acquired immunity.

Answer:

Differences between active acquired immunity and passively acquired immunity:

Question 14 What is an antigen?

Answer:

Antigen:-

Antigens are foreign materials that stimulate the immune system of the body by inducing the synthesis of specific antibodies and sensitising immunologically significant white blood cells.

Question 15 Mention the characteristic features of antigens.

Answer:

Characteristic features of antigens are as follows:

[1] Antigens are commonly proteins or polysaccharides in nature,
[2] Antigens are generally of high molecular weight. The minimum molecular weight of an antigen is 10000 Da.
[3] An antigen induces the synthesis of a specific antibody.

Question 16 What are the common sources of antigens?

Answer:

The common sources of antigens are as follows:

1. Surface proteins of bacteria and viral capsids are the common sources of antigens.
2. Different toxins, snake venom, sting poisons of bees, wasps, and scorpions act as antigens.
3. Secretory or excretory materials of bacteria or parasites contain antigens.
4. Some chemicals, drugs, pollen grains even food materials contain allergic antigens (allergens).

WBBSE Class 9 Life Science Question And Answer

Question 17 What are exogenous antigens?

Answer:

Exogenous Antigens:-

The antigens, which enter the body from outside, are called exogenous antigens. Exogenous antigens include different disease-causing germs, certain allergic food materials, chemicals, and pollen grains.
Passively acquired immunity Enters into the body from the mother’s body or from another animal source and Acts instantaneously

Question 18 What is an endogenous antigen?

Answer:

Endogenous Antigen:-

The antigenic materials, which are synthesized inside the body and are capable of inducing immune response are called endogenous antigens. Certain proteins present on the surface of RBC, cardiolipin of the mammalian heart, and prostate-specific antigens of the prostate gland are examples of endogenous antigens.

Question 19 What is an antibody?

Answer:

Antibody:-

Antibodies are immunoglobulin molecules, which are produced or remain in blood to counteract and inactivate specific antigens and thereby protect the body against their harmful effects.

WBBSE Class 9 Life Science Question And Answer

Question 20 What are ‘paratope’ and ‘epitope’?

Answer:

‘Paratope’ And ‘Epitope’:-

The part of the antibody that adheres to the antigen is known as ‘the paratope’ and the part of the antigen, attached to the paratope is known as ‘the epitope.

Question 21 How do antibodies work?

Answer:

Antibodies work through the following methods:

1. Antibodies or immunoglobulins bind to specific antigens to agglutinate and precipitate them.
2. Some antibodies bind to antigens to let those to be phagocytized by macrophage cells. antibodies
3. Some antibodies immobilize and dissolve antigens.

Question 22 How many types of antibodies are found in the human body?

Answer:

Types Of Antibodies Are Found In The Human Body:-

The human body contains five different types of antibodies or immunoglobulins. These are IgA, IgD, IgE, IgG, and IgM.

WBBSE Class 9 Life Science Question And Answer

Question 23. What is the primary immune response?

Answer:

Primary Immune Response:-

The reactions in the body in response to an antigen for the first time is called primary immune response. This response takes a little more time (10-17 days) for recognition of the antigen.

Question 24 What is the secondary immune response?

Answer:

Secondary Immune Response:-

The reactions in response to an antigen, already known to the body’s immune system, is known as secondary immune response. This response is very fast (2-7 days) because memory cells, already produced in the body, recognize the antigen and respond instantaneously.

Question 25 What do you mean by the first line of defense and second line of defense?

Answer:

First Line Of Defense And Second Line Of Defense:-

The first line of defense is the various types of physical and chemical barriers that prevent the entry of foreign agents into the body.

The second line of defense is non-specific resistance, which is also considered a function of innate immunity. The phagocytes, interferons, inflammatory reactions, natural killer cells, and the complement system are the components of the second line of defense.

Question 26 What is meant by primary lymphoid organ?

Answer:

Primary Lymphoid Organ:-

The organs, within which T and B lymphocytes attain maturity, are called primary lymphoid organs. Example-Thymus gland, the site of maturity of T cells and red bone marrow, the tissue where B cells mature, are the two primary lymphoid organs.

Question 27 What is a secondary lymphoid organ?

Answer:

Secondary Lymphoid Organ:-

Matured T and B lymphocytes are transferred to some other organs for further proliferation. These organs are known as secondary lymphoid organs. Example-All lymph glands, especially tonsils, and spleen are examples of secondary lymphoid organs.

WBBSE Class 9 Life Science Question And Answer

Question 28 What is meant by cell-mediated immunity?

Answer:

Cell-Mediated Immunity:-

The immune response, which involves the activation of the cytotoxic T lymphocytes and different phagocytic cells in destroying the pathogens or pathogen-infected cells within the body, is called cell-mediated immunity.

Question 29 What is a memory cell? State its role in immunology.

Answer:

Memory cell:

Memory cells are long-lived immune cells capable of recognizing foreign particles they were previously exposed to. These immune cells do not respond immediately when it first encounters an antigen but facilitates a more rapid secondary response when the antigen is encountered on a subsequent occasion. >> Function: Examples of memory cells are memory B cells and memory T cells. Unlike memory B cells, memory T cells do not produce antibodies. Re-exposure to the pathogens cause them to clone themselves immediately and as such respond to the infection more strongly.

Question 30 What do you mean by B cell and T cell?

Answer:

B Cell And T Cell:-

The major cells of the immune system are the WBCs called lymphocytes. The lymphocytes are of two types T lymphocytes or T cells and B lymphocytes or B cells. T lymphocytes form a cell-mediated immune system and B lymphocytes form a humoral or antibody-mediated immune system.

Question 31 What is a plasma cell? State its role in immunology.

Answer:

Plasma Cell And Role Of Immunology:-

Plasma cell: Plasma cells are a special type of B lymphocyte capable of secreting immunoglobulins or antibodies. These secrete huge numbers of antibody molecules into the blood, tissue fluid, and lymph. They live for only a few days.
Role: When antigens invade tissue fluid, plasma cells are stimulated to produce antigen-specific antibodies.

Question 32 What is interferon (IFN)?

Answer:

Interferon:-

Interferon is a group of proteins that is formed and released by the host cells in response to pathogens, especially virus. These are highly effective in combating hepatitis, influenza, etc.

WBBSE Class 9 Life Science Question And Answer

Question 33 What is MALT?

Answer:

MALT:-

The full form of MALT is Mucosa Associated Lymphoid Tissue. These types of lymphoid tissues are located within the lining of the respiratory tract, digestive tract, and urogenital tract and it constitutes 50% of the lymphoid tissues in the human body.

Question 34 What is the main objective of vaccination?

Answer:

Objective Of Vaccination:-

Generating memory cells in the blood to recognize a specific antigen for the quick triggering of immunological response in case of infection by the same pathogen in the future is the main objective of vaccination.

Question 35 What is the importance of vaccination?

Answer:

The importance of vaccination is as follows:

Biology and Human Welfare:

1. By means of vaccination specific antibody develops within our body. Memory cells develop in the body, which remain stored in the lymphatic system to counter any chance of infection by the same pathogen in the future.
2. Certain vaccines develop immunity for a lifetime and some others immunize the body for a certain period.

Question 36 What is meant by an attenuated vaccine?

Answer:

Attenuated Vaccine:-

The vaccines, which are prepared by living but inactivated pathogens (bacteria or viruses) are called attenuated vaccines. Examples-Vaccines of tuberculosis, mumps, influenza, and Oral polio vaccine (Sabin vaccine) belong to the attenuated vaccine.

Question 37 What is meant by a killed vaccine?

Answer:

Killed Vaccine:-

The vaccines, which are prepared with dead or inactivated bacteria or viruses, are known as killed vaccines. Examples-Vaccines of typhoid, cholera, whooping cough (pertussis), rabies, hepatitis B and Salk vaccine belong to the killed vaccine category.

WBBSE Class Nine Life Science

Question 38 What is a toxoid?

Answer:

Toxoid:-

Toxins collected from pathogenic micro-organisms are chemically detoxified keeping their antigenic property intact. These preparations are used as vaccines, which are called toxoids.
Examples: Tetanus and diphtheria vaccines are of this type.

Question 39 What is Tetanus toxoid?

Answer:

Tetanus Toxoid:-

It is an inactivated form of tetanus toxin obtained from Clostridium tetani, used to produce an active immunity to the toxin.

Question 40 What is meant by combination vaccines?

Answer:

Combination Vaccines:-

Certain vaccines are prepared with different antigens to immunize individuals against more than one disease by a single inoculation. These vaccines are called combination vaccines. Examples-DPT (Diphtheria, Pertussis, Tetanus) vaccine, and MMR (Mumps, Measles, Rubella) vaccine are of this type.

Question 41 What is the booster dose of the vaccine?

Answer:

Booster Dose Of The Vaccine:-

To maintain a steady stock of memory cells in the immune system certain vaccines are applied at regular intervals. These slots of vaccines are known as booster doses. Example-Booster dose of tetanus toxoid must be given after every ten years.

WBBSE Class Nine Life Science

Question 42 Why do you need the DPT vaccine? When should the DPT vaccine be given?

Answer:

DPT vaccine is a combination vaccine used for immunization against Diphtheria, Pertussis, and Tetanus.
The standard schedule is three primary doses at 6, 10, and 14 weeks and two boosters at 15-18 months and 5 years.

Question 43 Why do you need the MMR vaccine? Mention its type.

Answer:

MMR vaccine:

The MMR vaccine is a vaccine against Measles, Mumps, and Rubella (German measles). The first dose is generally given to children around 9-15 months of age, with a second dose at 15 months to 6 years of age, with at least 4 weeks between the doses.

Type: It is a type of live attenuated, combined vaccine.

Question 44 Mention the causative agents of diarrhea. How is the disease transmitted?

Answer:

Causative agents of diarrhea: Diarrhoea is caused by ETEC-Enterotoxigenic E. coli, Salmonella sp. (bacteria), and Rotavirus (virus).

Mode of transmission of diarrhea: This disease is transmitted through contaminated food and water.

Question 45. Write the common symptoms of diarrhea.

Answer:

Common symptoms of diarrhea are:

1. frequent watery stool
2. abdominal pain and cramps
3. disability to hold a bowel movement
4. nausea and fatigue
5. thirst and dehydration.

Question 46 Mention the names of different malaria-causing pathogens. How is malaria transmitted?

Answer:

Causative agents of malaria:

Malaria is caused by different species of Plasmodium, a parasitic protozoan. They are Plasmodium vivax, P. falciparum, P. malariae and P. ovale.

Transmission of malarial parasite:

Female Anopheles mosquito carries Plasmodium from a diseased individual to a healthy person.

Question 47 Write down the different symptoms of malaria.

Answer:

The symptoms of malaria are:

1. chilled feeling with severe shivering
2. severe headache
3. very high fever (104°F or more)
4. remission of fever with profuse sweating
5. fatigue
6. nausea.

WBBSE Class Nine Life Science

Question 48 Name the causative agent of diphtheria. How is the disease transmitted?

Answer:

The causative agent of diphtheria:

The causative agent of diphtheria is a bacterium named Corynebacterium

Mode of transmission of diphtheria:

Diphtheria is transmitted mainly through respiratory droplets. This disease is also spread by touching the body of an infected person and from contaminated materials like telephones, utensils, towels, handkerchiefs, etc.

Question 49 Mention the symptoms of diphtheria.

Answer:

The symptoms of diphtheria are:

1. Thick, gray coating over the pharyngeal wall and tonsils
2. Sore throat and hoarseness
3. Swelling of lymph glands near the neck
4. Distressed breathing and swallowing
5. Nasal discharge
6. High fever.

Question 50 Name the causative agent of pneumonia. How is the disease transmitted?

Answer:

Causative agent of pneumonia: Causative agent of pneumonia is a bacterium named Streptococcus pneumoniae.

Mode of transmission of pneumonia: The pathogens of pneumonia are transmitted through respiratory droplets from the nose and mouth of a sick person.

Question 51 Mention the symptoms of pneumonia.

Answer:

The symptoms of pneumonia are:

1. Severe cough
2. Distressed breathing
3. Chest pain, especially with cough
4. Fever
5. Breathless-ness
6. Fatigue.

Question 52 Name the causative agent of tetanus. How is the disease transmitted?

Answer:

Causative agent of tetanus: Causative agent of tetanus is Clostridium tetani.

Mode of transmission of tetanus:

The pathogen of tetanus is transmitted directly from soil through open wounds or injuries. Injuries from contaminated nails, knives, razors, surgical instruments, etc. also transmit this disease.

WBBSE Class Nine Life Science

Question 53 Mention the symptoms of tetanus.

Answer:

The symptoms of tetanus are:

1. Fever followed by jaw cramping
2. Spasm in stomach
3. Stiffness of muscles with severe pain
4. Trouble in swallowing
5. High blood pressure and fast heart rate.

Question 54 How is tuberculosis transmitted?

Answer:

Tuberculosis Transmitted:-

Tuberculosis is transmitted through respiratory droplets from the nose and mouth of a diseased person. Exhaled air of the patient carries pathogens of this disease. Inhaling this air from a distance of a few meters may infect another person with the same disease.

Question 55 Name the causative agent of tuberculosis. Mention the symptoms of tuberculosis.

Answer:

The causative agent of tuberculosis: Causative agent named of tuberculosis is the bacterium Mycobacterium tuberculosis.

Symptoms of tuberculosis:

1. Night fever with sweating
2. Dry cough with blood-tinted sputum
3. Significant weight loss
4. Fatigue.

Question 56 Name the causative agent of dengue. How is dengue transmitted?

Answer:

Causative agent of dengue: Causative agent of dengue is Flavivirus.

Mode of transmission of dengue:

Female Aedes aegepti mosquito (which is a blood-sucking ectoparasite) carries the dengue virus from a diseased person to a healthy individual.

WB Class 9 Life Science Question Answer

Question 57 Mention the symptoms of dengue.

Answer:

The symptoms of dengue are:

1. High fever with severe headache
2. Pain behind the eyes
3. Severe body aches and joint pain
4. Rash over the skin
4. Moderate bleeding from gums.

Question 58 Name the causative agent of hepatitis A. How is hepatitis A transmitted?

Answer:

Causative agent of hepatitis A: Causative agent of hepatitis A is HAV or Hepatitis A Virus.

Mode of transmission of hepatitis A:

This virus comes out through the feces of a person, infected with hepatitis A. The pathogen is then transmitted through contaminated food (raw vegetables) or drinks (water) in a healthy person. Therefore, in other words it can be stated that this infection is transmitted through fecal-oral route.

Question 59 Mention the symptoms of hepatitis A.

Answer:

The symptoms of hepatitis A are:

1. Nausea and vomiting
2. Liver pain
3. Loss of appetite
4. Darkish urine
5. Yellowing of skin and eyes.

Question 60 Name the causative agent of hepatitis B. How is hepatitis B transmitted?

Answer:

The causative agent of hepatitis B: Causative agent with soap and disinfecting lotion. of hepatitis B is HBV or Hepatitis B Virus.

Mode of transmission of hepatitis B:

This virus is carried by blood or other body fluids. It is transmitted through transfusion of contaminated blood and sharing the same injection needle with a patient. This virus may pass through the placenta, therefore, infect a fetus of a diseased mother. It may be transmitted by sexual contact also.

Question 61 Mention the symptoms of hepatitis B.

Answer:

The symptoms of hepatitis B are:

1. Nausea and vomiting
2. Liver pain
3. Loss of appetite
4. Darkish urine
5. Yellowing of skin and eyes.
6. Severe fatigue.

Question 62 Name the causative agent of AIDS. How is AIDS transmitted?

Answer:

The causative agent of AIDS: The causative agent of AIDS is HIV or Human Immunodeficiency Virus.

Mode of transmission of AIDS:

The virus of AIDS is transmitted by transfusion of contaminated blood, sharing the same injection needle with a patient, through unsafe sexual contact, from infected mother to fetus through placental circulation.

WB Class 9 Life Science Question Answer

Question 63 Mention the symptoms of AIDS.

Answer:

The symptoms of AIDS are:

1. Recurrent fever
2. Common cold-like symptoms
3. Frequent diarrhea
4. The quick loss of weight
5. Swelling of glands in the groin
6. Fatigue
7. Joint pain
8. Persistent skin rashes.

Question 64 What is meant by washing?

Answer:

Washing:-

The process of disinfecting hands and other body parts, garments, utensils, and raw food matters, like fish, meat, vegetables and fruits with clean water, soap, detergents, or germicidal locations is known as washing.

Question 65 Mention the role of different washing materials.

Answer:

The role of different washing materials is as follows:

1. Water is used to wash all items.
2. Detergents are used to wash garments, bedding, and utensils.
3. Floor cleaners are used to clean floors of rooms and toilets.
4. Soap, shampoo, and shower gels are used in bathing.
5. Hand is washed with soap and disinfecting lotion.

WB Class 9 Life Science Question Answer

Question 66 Briefly describe the importance of brushing your teeth.

Answer:

Importance Of Brushing Your Teeth:-

The unhygienic oral condition leads to different problems like tooth decay, gum disease, bad breath, pyorrhoea, loosening and falling of teeth. Proper brushing with toothpaste helps in reducing plaque and germ buildup in the mouth and reduces the chances of oral problems. For this purpose brushing of teeth is to be done essentially before going to bed.

Question 67 Why is bathing important for good health?

Answer:

Bathing Important For Good Health:-

The population of different bacteria, fungi, and ectoparasites grows fast on unclean body surfaces. Sweat and sebum provide the germs a good medium for nutrition and growth.

An unclean body surface leads to several skin infections. By regular bathing, these germs are washed off. Therefore, bathing is important to maintain good health.

Question 68 What should be the proper bathing technique?

Answer:

Proper Bathing Technique:-

To clean the body surface showering with clean water is necessary. Then soap or bathing gel is to be applied and then rubbed with a scrubber to create rich foam. More attention is to be given to the hidden parts like armpits, and groins, as these regions provide good places for germ build-up. Finally, the foam is to be cleared with adequate water to get clean and hygienic skin.

Question 69. Why are washing and sun drying of garments, bedding, bathing towels, and handkerchiefs essential for maintaining hygiene?

Answer:

Pathogens of scabies, ringworm, eczema, and a number of allergens spread through contaminated garments, beddings, bathing towels and handkerchiefs. Washing can reduce the population of pathogens from these materials. Therefore, washing and sun drying of these items is essential for maintaining good hygiene.

Question 70 Why is washing of hand essential before ing of hands essential before taking food?

Answer:

We commonly take food by hand. A contaminated hand may carry the pathogens of various diseases like diarrhea, dysentery, hepatitis A, cholera, and gastroenteritis. By washing hands before taking food, the occurrence of these diseases can be reduced to a great extent.

Question 71 Why an open wound should be washed with germicidal lotion?

Answer:

Skin acts as a great barrier against the entry of germs into our bodies. However, open wounds become a good entry point for various germs. Therefore, any open wound is to be washed with germicidal lotions to kill the germs in the wound and at its periphery. After washing, the wound must be covered with a sterilized bandage, gauge, or cotton to resist the entry of germs through it.

Question 72 What do you mean by disinfectants?

Answer:

Disinfectants:-

Disinfectants are chemical agents that kill or inhibit the growth of microorganisms on inanimate objects. It is more toxic to humans. e.g. phenyl, methylated spirit.

 

Chapter 4 Biology And Human Welfare Immunity And Human Answer In A Single Word Or Sentence

Question 1 What is the name of the reaction shown by the body against any pathogen?
Answer: The reaction shown by the body against any pathogen is commonly called the immune response.

Question 2 What are pathogens?
Answer: A pathogen is a disease-causing microorganism.

Question 3 Which type of immunity develops by birth?
Answer: Innate immunity develops by birth.

Question 4. Which type of immunity is provided by neutrophils?
Answer: Neutrophils provide innate immunity to the body.

Question 5. Which characteristic ability of antigen activates the immune system of the body?
Answer: The immunogenicity of antigens activates the immune system of the body.

Question 6. Which characteristic ability of an antigen makes it compatible to the antibody?
Answer: The antigenicity of an antigen makes it compatible to the antibody.

Question 7. Which is the first line of defense in our immune system?
Answer: Skin and mucous membranes provide the first line of defence in our body’s immune system.

Question 8. Which is the second line of defence in our immune system?
Answer: Phagocytic white blood cells like neutrophils and monocytes provide the second line of defence in our body’s immune system.

Question 9. Which is the third line of defence of human immune system?
Answer: Acquired immunity provided by different types of T and B lymphocytes provides the third line of defence to human immune system.

Question 10. What is the name of the chemical, which is produced inside the body to resist a toxin?
Answer: Antitoxin is produced inside the body to resist a toxin.

Question 11. How does an immunoglobulin G molecule appear?
Answer: Immunoglobulin G molecules appears like English letter ‘Y’

Question 12. Which is the most abundant antibody present in human blood?
Answer: Immunoglobulin G is the most abundant antibody present in human blood.

Question 13. Which type of antibody is present in different body fluids and secretory materials in human body?
Answer: Immunoglobulin A is present in different body fluids and secretory materials in the human body.

Question 14. Which is the largest antibody present in our body?
Answer: Immunoglobulin M is the largest antibody present in our body.

Question 15. In which antibody do five molecules stay as a cluster?
Answer: In immunoglobulin M, five molecules stay in a cluster.

Question 16. Where do B lymphocytes mature?
Answer: B lymphocytes or B cells mature in the red bone marrow.

Question 17. How many globulin chains combine to prepare an immunoglobulin G molecule?
Answer: Two heavy and two light globulin chains combine to prepare an immunoglobulin G molecule.

Question 18. How do the globulin chains remain tied together in an immunoglobulin G molecule?
Answer: In an immunoglobulin G molecule the heavy and light chains remain tied together by disulfide bonds.

Question 19. Which type of antibody can penetrate the placental barrier to reach the fetal blood from the mother’s body?
Answer: IgG can penetrate the placental barrier to reach the fetal blood from the mother’s body.

Question 20. Which antibody is present in tears?
Answer: IgA is present in tears.

Question 21. Which antibody is synthesized first in the human fetus?
Answer: The antibody synthesized first in a human fetus is IgM.

Question 22. Which antibody protects our body against allergens?
Answer: IgE protects our body against allergens.

Question 23. What are allergens?
Answer: The substances which trigger allergies are called allergens.

Question 24. What is meant by vaccination?
Answer: Inoculation of the body with vaccines to develop active acquired immunity against specific disease-causing germs or toxins is called vaccination.

Question 25. What is the full form of the DPT vaccine?
Answer: Full form of DPT is Diphtheria, Pertussis (whooping cough), and Tetanus.

Question 26 What is the full form of TT?
Answer: Full form of TT is Tetanus toxoid.

Question 27 Which vaccine did Calmette and Guerin discover?
Answer: Calmette and Guerin discovered the vaccine against tuberculosis.

Question 28 Who discovered the vaccine of polio?
Answer: Jonas Salk discovered the vaccine of polio.

Question 29. Who discovered the Oral Polio Vaccine?
Answer: Albert Sabin discovered the Oral Polio Vaccine.

Question 30. What is the full form of BCG?
Answer: Full form of BCG is Bacillus Calmette-Guerin.

Question 31. What is the full form of MMR?
Answer: Full form of MMR is Mumps-Measles-Rubella.

Question 32. What is the full form of ATS?
Answer: Full form of ATS is Anti-Tetanus Serum.

Question 33. What is the full form of OPV?
Answer: Full form of OPV is Oral Polio Vaccine.

Question 34 Give an example of attenuated viral vaccines.
Answer: Vaccines of mumps, measles, rubella, and chickenpox belong to attenuated viral vaccines.

Question 35. What is the sub-unit vaccine?
Answer: The vaccine which is prepared by a certain molecular part of a pathogen, a viral protein for instance, is called a sub-unit vaccine.

Question 36. Give an example of a sub-unit vaccine.
Answer: The vaccine of Hepatitis B is a sub-unit vaccine.

Question 37. To which kingdom of the living world does the malaria pathogen belong?
Answer: The malaria pathogen belongs to the kingdom Protista.

Question 38. What is the other name of ‘Break Bone fever’?
Answer: The other name of ‘Break Bone fever’ is dengue.

Question 39. Which disease is commonly known as ‘Lock Jaw’ disease?
Answer: Tetanus is commonly known as ‘Lock-Jaw disease’.’

Question 40. Name a viral disease which is transmitted by mosquitoes.
Answer: Dengue is a viral disease that is transmitted by mosquitoes.

Question 41. Which type of hepatitis is transmitted through contaminated food and drink?
Answer: Hepatitis A is transmitted through contaminated food and drink.

Question 42. Name a virus, which causes severe diarrhea.
Answer: Rotavirus causes severe diarrhea.

Question 43. Name a disease caused by a retrovirus.
Answer: AIDS is caused by a retrovirus.

Question 44. What is full form of AIDS?
Answer: Full form of AIDS is Acquired Immune Deficiency Syndrome.

Question 45. Which day is observed as World AIDS Day?
Answer: Every year 1st December is observed as World AIDS Day.

Question 46. Name two common household disinfectants.
Answer: Phenyl and bleaching powder are two common household disinfectants.

Question 47. How can you disinfect your hands without using water?
Answer: Alcohol-based hand sanitizers can disinfect hands without water.

Question 48. Which day is observed as World Health Day?
Answer: Every year 7th April is observed as World Health Day.

Question 49. Mention the full form of the ‘WASH’ program as proposed by UNICEF.
Answer: The full form of the WASH program is-Water and Sanitation Hygiene program.

Chapter 4 Biology And Human Welfare Immunity And Human Fill In The Blanks

1. The ability of the body to resist the harmful effect of pathogens is known as Immunity

2. Immune system is formed for protecting our body from the hands of foreign invaders.

3. Acquired Active immunity develops naturally due to the introduction of antigens.

4. Antibody is produced in the body by the influence of Antigen

5. Thymus gland is a Primary lymphoid organ.

6. There are 5 types of antibodies in our body.

7. Antibody is Y shaped.

8. Antibody is made up of 4 a polypeptide chain.

9. In ‘T’ cells, ‘T’ indicates Thymus

10. Suppressor cells destroy T cells and T cells.

11. Plasma cells produce specific antibodies to inactivate Antigen

12 Two types of B cells are plasma cells and Memory cells.

13 Memory cells stay in Lymph glands.

14 An Allergen is a substance that can cause an allergic reaction by histamine secretion.

15 Edward Jenner is the founder of vaccinology.

16 The first smallpox vaccine was discovered by Edward Jenner

17 BCG vaccine introduced by Calmette Guerin.

18 BCG vaccine is a type of Attenuated vaccine.

19 Smallpox vaccine is a Heterotypic vaccine.

20 Tetanus vaccine is prepared by inactivated Toxin from Clostridium tetani.

21 A triple antigen is DPT

22 DPT vaccine is applied in the prevention of Diptheria, pertussis, and tetanus.

23 Diarrhoea is a Water-borne disease.

24 Mycobacterium tuberculosis is a pathogenic Bacterium

25 Repetitive actions of the muscle cramps, spasms, or tremors are symptoms of Tetany

26 The number of Bilirubin increases in the blood due to jaundice.

27 Methylated spirit and phenyl a type of Disinfectant

28 ‘WASH’ program was developed by UNICEF

Chapter 4 Biology And Human Welfare Immunity And Human State True Or False

Question 1. Antigens mainly include proteins.

Answer: True

Question  2. Toxic chemicals like snake venom can act as antigens.

Answer: True

Question  3. The epitope is part of an antibody.

Answer: False

Question 4. IgM is a pentamer.

Answer: True

Question  5. IgA is present in tears.

Answer: True

Question  6. Vaccination develops artificial active immunity.

Answer: True

Question  7. A vaccine against Hepatitis B is an example of a subunit vaccine.

Answer: True

Question  8. Stiffness of muscles with severe pain is a symptom of diarrhea.

Answer: False

Question  9. Tuberculosis is a virus-borne disease.

Answer: False

Question  10. Yellowing of the skin and eye is a symptom of pneumonia.

Answer: False

Question  11. Female Aedes aegypti mosquito carries Flavivirus from a diseased person to a healthy individual.

Answer: True

Question  12. AIDS is transmitted through drinking water.

Answer: False

Chapter 4 Biology And Human Welfare Immunity And Human Match The Columns

Answer: 1-D; 2-A; 3-F 4-B; 5-C; 6-G

Answer: 1-E; 2-A; 3-D; 4-B; 5-C; 6-G

Answer: 1-B; 2-C; 3-D; 4-A; 5-F; 6-G

Chapter 4 Biology And Human Welfare Immunity And Human Find The Odd One Out

Question 1. Immunity, IgG, B lymphocytes, Bacteria

Answer: Bacteria

Question 2. Innate immunity, Acquired immunity, In born immunity, HCl of stomach

Answer: Acquired immunity

Question 3. Thomas gland, Helper T cell, Cellular immunity

Answer: B cell

Question 4. IgA, IgG, IgM, MMR

Answer: MMR

Question 5. DPT, OPV, BCG, HIV

Answer: HIV

Question 6. ATS, DPT, MMR, Lysozymes

Answer: Lysozymes

Question 7. Diarrhea, Cholera, Night blindness, AIDS

Answer: Night blindness

Question 8. Excessive fever, Joint pain, Skin rash, Pneumonia

Answer: Pneumonia

Question 9. Pain behind eyes, Rash over the skin, Severe headache, Typhoid

Answer: Typhoid

Question 10. Malignant malaria, High fever with shivering, Anaemia, Diarrhoea

Answer: Diarrhoea

Question 11. AIDS, Polio, Hepatitis-B, Tuberculosis

Answer: Tuberculosis

Question 12. Rotavirus, Salmonella, Entamoeba, Corynebacterium

Answer: Corynebacterium

Chapter 4 Biology And Human Welfare Immunity And Human Fill In The Blanks By Looking At The First Pair

1. IgG: Monomer:: IgM: Pentamer

2. Allergy: IgE:: Secretory antibody: IgA

3. B lymphocyte Humoral immunity:: T lymphocyte: Cell-mediated immunity

4. Maturation of T cell Thymus gland:: Maturation of B cell: Bone marrow

5. Vaccine: Active immunity:: ATS injection: Passive immunity

6. Secretion of cytokines: Innate immunity:: Application of vaccine: Acquired Immune response

7. TB: BCG:: Polio: OPV

8. HIV: T lymphocyte:: Plasmodium: RBC

9. Measles: Rubella virus:: AIDS: HIV

Chapter 4 Biology And Human Welfare Immunity And Human Among The Four Concepts Given, Three Of Them Belong To One. Find That

Question 1. Lysozyme, HC1, Mucous membrane, Innate immunity

Answer: Innate immunity

Question 2. Sebum, Saliva, Chemical barrier, Tears

Answer: Chemical barrier

Question 3. Carcinogenicity, Antigen, Allergenic, Anti genicity

Answer: Antigen

Question 4. Agglutination, Antibody, Humoral immunity, B cell

Answer: Humoral immunity

Question 5. γ globulin, Paratope, Disulphide bond, Heavy chain

Answer: γ globulin

Question 6. DPT, Vaccine, ATS, BCG

Answer: Vaccine

Question 7. Pneumonia, Diptheria, Tetanus, Bacterial diseases

Answer: Bacterial diseases

Question 8. Anemia, High temperature, Splenomegaly, Malaria

Answer: Malaria

Question 9. Destruction of T cells, HIV, Unprotected sexual intercourse, AIDS

Answer: AIDS

Question 10. Soap, Components of washing, Detergent, Methylated spirit, Water

Answer: Components of washing