In case of malaria, the rupture of RBCs is associated with release of a toxic substance called, _________, which is responsible for the chill and high fever recurring after every three to four days.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Haemozoin
In malaria, the Plasmodium parasites burst the red blood cells, and a toxin set free at that moment causes the fever.
Option (2) Haemozoin — Correct. Haemozoin is the toxin named in the book; the other three options are not toxins of Plasmodium.
Note: A similar question was also asked in CUET (UG) 2025 on 23-05-2025 (Slot 2).
NCERT Extract:
Common Diseases in Humans – “… Let us take a glance at the life cycle of Plasmodium (Figure 7.1). Plasmodium enters the human body as sporozoites (infectious form) through the bite of infected female Anopheles mosquito. 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.”
