Read the given passage carefully and answer the questions.
Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings. Sustained high fever (39° to 40°C), weakness, stomach pain, constipation, headache and loss of appetite are some of the common symptoms of this disease. Typhoid fever could be confirmed by Widal test. Plasmodium enters the human body as sporozoites. The parasites initially multiply within the liver cells and then attack the red blood cells (RBCs) resulting in their rupture. The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days. There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa-associated lymphoid tissue (MALT). In our body, cell growth and differentiation is highly controlled and regulated. In cancer cells, there is breakdown of regulatory mechanisms. Normal cells show a property called contact inhibition by virtue of which contact with other cells inhibits their uncontrolled growth. Cancerous cells just continue to divide giving rise to masses of cells called tumors. Tumors are of two types: benign and malignant. Cannabinoids are a group of chemicals, which interact with cannabinoid receptors present principally in the brain. Generally taken by inhalation and oral ingestion, these are known for their effects on cardiovascular system of the body.
In which organ of the human body, cannabinoid receptors are principally present?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Brain
Option (1) Kidney — Incorrect. The kidney is the organ that filters blood and forms urine. It is not where cannabinoids act.
Option (2) Lungs — Incorrect. Cannabinoids are often taken by inhalation, so they enter the body through the lungs. But the lungs are only the way in. The receptors they act on lie elsewhere.
Option (3) Heart — Incorrect. Cannabinoids are known for their effects on the cardiovascular system, that is the heart and blood vessels. An effect on an organ is not the same as the place of the receptors.
Option (4) Brain — Correct. Cannabinoids are chemicals obtained from the plant Cannabis sativa, used as marijuana, hashish, charas and ganja. They interact with cannabinoid receptors present principally in the brain.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.