Class 9 SELINA Solutions Biology Chapter 16 - Diseases: Cause And Control
Diseases: Cause And Control Exercise Ex. 1
Solution A
1. (c) pandemic
2. (d) AIDS
3. (c) Anopheles mosquito
4. (d) Entamoeba
5. (d) Tuberculosis
6. (b) Acquired Immuno Deficiency Syndrome
Solution B.1
(a) F (False). Filariasis is transmitted by the Culex mosquito.
(b) T (True)
(c) F (False). BCG vaccine is used for tuberculosis.
(d) F (False). Louis Pasteur discovered a cure for rabies.
(e) F (False). AIDS is caused by a virus.
(f) T (True)
(g) T (True)
(h) F (False). Chicken pox and hepatitis are viral diseases.
(i) T (True)
(j) F (False). AIDS is caused by HIV virus.
(k) T (True)
(l) F (False). Smallpox has been eradicated from India.
(m) F (False). The disease filariasis is caused by the filarial worm Wuchereria bancrofti.
Solution B.2
AIDS : Acquired Immunodeficiency Syndrome
Solution B.3
(a) Viruses
(b) BCG
(c) Lungs
(d) AIDS
(e) Vaccine
(f) Tsetse fly
(g) Virus
(h) Elephantiasis
Solution C.1
Infection: The transmission of disease from one person to another is called infection.
Pathogen: Disease-causing micro-organism is called a pathogen.
Incubation period: Incubation period is the period between the entry of germs and the appearance of the first symptoms of the disease.
Allergen: An antigenic substance capable of producing immediate hypersensitivity allergy is called an allergen.
Solution C.2
- Direct contact: Person to person, animal to person and expected mother to child
- Indirect contact: Doorknob, phone, etc.
- Droplet transmission: Sneezing, coughing, etc.
- Particle transmission: Air particles can transfer infectious diseases
- Bites and Stings: Mosquitoes, lice, ticks, etc.
- Food Contamination: Food, beverages, etc.
Solution C.3
|
NON-INFECTIOUS DISEASES |
CAUSE OF THE DISEASE |
|
Asthma |
Allergy |
|
Cataract |
Ageing |
|
Beri-Beri |
Nutritional deficiency |
|
Cancer |
Carcinogens like chemicals, tobacco smoking, pollution etc. |
Solution C.4
Causative germ of AIDS:
HIV (Human immunodeficiency virus)
Transmission of AIDS:
(a) Sexual intercourse
(b) Mother to child transmission
(c) Contaminated blood transfusions
Solution D.1
(a) BCG: It is a vaccine which is effective against the bacterial disease tuberculosis (TB). It develops immunity to TB. BCG stands for Bacillus Calmette Guerin.
(b) Incubation period: It is the period between the entry of germs and the appearance of the first symptoms of the disease. Example: Incubation period of pneumonia is 1-3 days.
(c) Chicken pox: It is a viral disease caused by the Herpes Varicella zoster virus. It spreads rapidly by close contact with an infected person. A live attenuated vaccine containing Varicella is administered to children of 12-18 months for active immunisation.
(d) Hepatitis A: It is a viral disease caused by Hepatitis A virus which results in inflammation of the liver. It has an incubation period of 14-45 days. It is mainly transmitted through contaminated food and water.
Solution D.2
|
Disease |
Causative agent |
Symptoms |
Prevention |
|
Malaria |
Protozoan, Plasmodium |
Chills, high fever, profuse sweating, severe headache, nausea, vomiting, fatigue and body pain |
Destruction of mosquitoes at all stages and avoid mosquito bites by using mosquito nets or repellents |
|
Chicken pox |
Virus, Varicella zoster |
Highly irritating rashes near the chest and back, gradually spreading to the arms, legs, face and head |
Active immunisation by administering live attenuated vaccine containing Varicella |
|
Tuberculosis |
Bacterium, Mycobacterium tuberculosis |
Persistent cough, afternoon fever, bloody mucus, loss of weight, fatigue and chest pain |
BCG vaccination and isolation of the patient |