Humans are bilateral animals that have holoblastic rotational cleavage. Conidiogenous cells are holoblastic and also hyaline. The fertilized zygote undergoes rotational holoblastic cleavage. Holoblastic cleavage is the complete division of cells. In bilateral animals cleavage can be either holoblastic or meroblastic depending on the species. Eggs are small and yolky, and cleavage is holoblastic, radial and equal. In the life cycle of "Elysia chlorotica", cleavage is holoblastic and spiral. Sea stars are deuterostomes and the first cleavage begins shortly after fertilization and is holoblastic. Its conidiogenous cells are holoblastic and smooth, while the conidia are aseptate and subglobose.