In some viral infections, number of platelets are reduced quickly. Platelets are essential because: (a) they along with red blood cells carry oxygen. (b) platelets are important to carry food to cells through blood. (c) platelets remove carbon dioxide from blood. (d) platelets have a role in blood clotting.

Platelets, also known as thrombocytes, are specialized blood cell fragments that play a critical role in hemostasis. Their primary function is to circulate throughout the body and plug leaks in blood vessels by facilitating blood clotting at points of injury [1]. When a vessel is damaged, platelets rush to the site to form a plug or thrombus, which prevents excessive blood loss. In contrast, other blood components handle different tasks: red blood cells (erythrocytes) are responsible for transporting oxygen via hemoglobin [2], while plasma transports food, carbon dioxide, and nitrogenous wastes in dissolved form [2]. Viral infections can lead to thrombocytopenia, a condition characterized by a significant reduction in platelet count due to increased consumption, destruction, or direct viral interaction with megakaryocytes [1]. This reduction increases the risk of abnormal bleeding and bruising because the body's clotting mechanism is compromised.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Maintenance by platelets > p. 94
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.7 > p. 91