Olympiad Test: Why do We Fall Ill- 2 - Class 9 MCQ

Cancer is a malignant tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis.

Tuberculosis, or TB, is an infectious bacterial disease caused by Mycobacterium tuberculosis, which most commonly affects the lungs. It is transmitted from person to person via droplets from the throat and lungs of people with the active respiratory disease. The bacteria release toxins known as tuberculin which destroys the organs it infects. The symptoms of active TB of the lung are coughing, sometimes with sputum or blood, chest pains, weakness, weight loss, fever, and night sweats. Tuberculosis is treatable with a six-month course of antibiotics.

House flies are the vectors of several infectious agents. The pathogen may attach with flies when they sit on the waste materials. They cause typhoid, cholera, salmonellosis, dysentery, tuberculosis, anthrax, and parasitic worms carried to human food on the fly’s body parts or in its regurgitations of defecations.

Malaria is caused by the toxins produced in the human body by malarial parasite Plasmodium. Malarial parasite is carried from the infected to the healthy persons by the female Anopheles mosquito.

The protozoa that are infectious to humans.

Sleeping sickness is caused by the protozoa Trypanosoma brucei.

Kala-azar is caused by protozoan parasites of the Leishmania genus.

Malaria is caused by the protozoa known as plasmodium.

Infectious disease can be easily transmitted from one person to the other. These are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi.

Staphylococci are the bacteria responsible for causing acne.

Public hygiene may be described as the activity which is associated with the population or the public to maintain cleanliness and good health. The drinking water should be kept clean which prevents the transmission of the water-borne diseases in the population. This is considered as a part of public hygiene.

Jaundice refers to the yellow color of the skin and whites of the eyes caused by excess bilirubin in the blood. Bilirubin is a yellow pigment that is formed by the breakdown of dead red blood cells in the liver. Normally, the liver gets rid of bilirubin along with old red blood cells. Jaundice occurs when the liver does not break down bilirubin the way it is supposed to because the liver might be damaged and unable to perform this process.

Ascaris lumbricoides is a common roundworm seen in the small intestine where they live, develop, and molt. It causes ascariasis.