The cleavage pattern of an embryo is controlled by the positioning and orientation of the mitotic spindles. Mitotic spindles may be attracted to particular areas of egg cortex. The mitotic spindle tends to align itself perpendicular to the longest dimension of a cell. The cleavage plane is always perpendicular to the axis of the mitotic spindle. Induction a. Induction is an interaction between cells or tissues that changes the determined state of at least one partner.
Most inductive interactions occur during oogenesis.
The earliest inductive event in amphibian development is neural induction. Animal cells induce their vegetal neighbors to form mesoderm. Dorsal vegetal blastomeres induces neighboring equatorial cells to form notochord. Dorsal equatorial cells induce their lateral neighbors to form intermediate mesoderm. The following statements are erroneous.