Why do we fall ill Class 9 Worksheet Science

Q.1. Fill in the blanks

(i) The Immune system helps in reducing the number of microbes in body and thus controls the disease.
(ii) Vectors are the animals that can carry the pathogen from unhealthy person to a healthy person.
(iii) Typhoid is caused by bacteria Salmonella typhi.
(iv) Genetic disorders of deficiency of nutrient are the examples of factors that can cause Non-infections diseases.
(v) Chronic disease is  a long duration, slow developing, disabling disease.

Q.2. Which one of the following causes kala-azar?
(a) Ascaris
(b) Trypanosome
(c) Leishmania
(d) Bacteria

Correct Answer is Option (c)

Q.3. If you live in a overcrowded and poorly ventilated house, it is possible that you may suffer from which of the following diseases.
(a) Cancer
(b) AIDS
(c) Air borne diseases
(d) Cholera.

Correct Answer is Option (c)

Q.4. The chemical that kill or stop the growing of certain kinds of microbes are called:
(a) Vaccines
(b) Microbes
(c) Antibiotics
(d) Fungi

Correct Answer is Option (c)

Q.5. Which one of the following is not important for individual health?
(a) Living in clean space
(b) Good economic condition
(c) Social equality and harmony
(d) Living in a large and well-furnished house.

Correct Answer is Option (d)

Q.6. Name the approaches generally adopted to treat infectious diseases.

Vaccines were first developed by Edward Jenner for the treatment of smallpox.
Polio and Tuberculosis can be prevented by using vaccine.

Q.7. How are diseases diagnosed by physician?

The malfunctioning of organs produces external symptoms of diseases. Symptoms indicate that there is something ‘wrong’ within the body. On the basis of symptoms doctor diagnosed the diseases.

Q.8. Which bacterium causes peptic ulcers? Who discovered the above pathogen?

Peptic ulcer is caused by bacterium Helicobacter pylori, it was discovered by Robin warren and Barry Marshall.

Q.9. What is peptic ulcer?

Peptic ulcer is a disease in which patient is suffering from acidity related pain and bleeding in the stomach and duodenum, due to stressful life style.

Q.10. Define carriers. Give two examples.

Carriers are the organisms which harbor disease-causing germs without showing away sign of disease themselves, but have the ability to infect other healthy individuals.
For Example: Housefly, female insect Anopheles.

Q.11. What are the different aspects of maintaining good health?

Different aspects for maintaining good health:

• Community health: It involves all the factors relating to personal health along with the services necessary for providing good health for the community.
• Personal health (hygiene): It is the science of preserving and promoting health mainly through the active efforts of an individual. It is practiced through active, sanitary habits and healthy way of life.
• Exercise, relaxation and sleep: Regular exercise is very necessary to keep the body fit. Proper sleep of about 6-8 hours is essential, Relaxation is very essential for good health.
• Nutrition: Optimum nutrition is essential for maintenance of good health. One should take sufficient and balanced food for maintaining good health.

Q.12. What are the causes of diseases?

Causes of diseases are:

• Infection by micro – organisms: Bacteria, virus, fungi, protozoa and worms cause communicable diseases.
• Malfunctioning of body organs.
• Deficiency of one or more nutrients.
• Genetic factors
• Polluted environment.

Q.13. What are the means of spread of diseases?

Diseases spread through:

• Air: When an infected person sneezes or coughs or spits, a healthy person standing nearby can inhale these droplets, causing infection in that person.
• By water: Some diseases can spread from one person to another when a sick person’s stools gets into water. The people drinking the infected water thus get the disease.
• By physical contact: Some of the diseases like AIDS, syphilis and gonorrhea spread by sexual contact. These diseases are not transmitted by casual physical contact like handshakes, hug’s, sports like wrestling and other ways in which we touch other socially.

Q.14. What is inflammation? What are the changes occur during inflammation?

It is the recruitment process by immune system in which immune system recruits many cells to the affected tissue to kill the disease causing germs.
During this process, certain local effects such as swelling and pain and general effects such as fever may develop.

Q.15. What precautions can you take in your school to reduce the incidence of infectious diseases?

To reduce the incidence of infectious diseases in my school the precautions will include:

• Isolating diseased students and clean surroundings
• Clean food and purified drinking water
• Not eating junk food and open/uncovered food materials