Final answer:
Granulocytes are leukocytes characterized by a lobed nucleus and granules in the cytoplasm. The most abundant type of granulocyte is the neutrophil, which is the first responder during infection or injury and is responsible for phagocytosis of bacteria and other foreign particles.
Step-by-step explanation:
Granulocytes are leukocytes characterized by a lobed nucleus and granules in the cytoplasm. The most common type of granulocyte is the neutrophil, which constitutes about 50-70% of all leukocytes in the body. Neutrophils are the first responders during infection or injury and are responsible for phagocytosis of bacteria and other foreign particles. They are attracted to the site of infection by chemical signals and release toxins to kill the invading pathogens. Therefore, neutrophils are the most abundant type of granulocyte because of their crucial role in the immune response.