The correct option is (a) 1 only.
Explanation
Blood coagulation, or clotting, is a physiological mechanism that prevents excessive blood loss following an injury or trauma. It involves a complex cascade of reactions leading to the formation of a solid mass called a clot.
Statement-wise Analysis
- Statement 1 is Correct: A clot is formed primarily to plug a cut or injury in a blood vessel. This mechanism stops bleeding (hemostasis) and prevents the excessive loss of blood from the body.
- Statement 2 is Incorrect: The formation of a clot is primarily initiated by platelets (thrombocytes) found in the blood. When platelets encounter an injured vessel, they release specific factors that trigger the coagulation cascade. White blood cells (leukocytes) are primarily responsible for the body's immune defense mechanisms, not blood clotting.
Key Takeaway
Platelets (thrombocytes) and plasma proteins like fibrinogen are essential for blood clotting, whereas white blood cells are involved in immunity.