Answer:
Three modes of glandular secretion are as follows:
Apocrine secretion:
Apocrine secretion may be defined as the secretion in which the cells bud out their secretion through plasma membrane. The extracellular membrane bound vesicles are produced in apocrine secretion.
Merocrine secretion:
Merocrine secretion may be defined as the secretion in which the cells are secreted via the process of exocytosis from the secretory cells in the lumen. No part of gland is lost during this secretion.
Holocrine secretion:
Holocrine secretion may be defined as the secretion in which cell secrete its content by the rupture of plasma membrane. The cells are completely destroyed and secrete their product in the lumen.