Ans. Cleavage is the rapid division of cells that occurs after fertilization. It is an important process in embryonic development as it leads to the formation of a multicellular embryo.The phases of cleavage include the zygote, two-cell stage, four-cell stage, eight-cell stage, morula, and blastula. During cleavage, the embryo undergoes cell division without a significant increase in overall size. This allows for the distribution of genetic material and cytoplasmic components to each new cell, ensuring that each cell has the necessary resources for further development.The phases of cleavage are important in embryonic development because they determine the number and arrangement of cells in the developing embryo. This early cell division sets the stage for subsequent differentiation and specialization of cells, ultimately leading to the formation of different tissues and organs in the developing fetus.