The reason for which the vertical division of the eight-cell stage sea urchin results in a normal larvae, but the horizontal division leads to the development of abnormal larva. Introduction: Cleavage is the division of zygote in a specified pattern. It occurs immediately after fertilization and results in formation of individual cells called blastomeres. Sea urchins belong to the class Echinodermata. They are globular and spiny creatures that are exclusively marine. They are characterized by radial and holoblastic cleavage.

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Chapter 47, Problem 6IQ

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To explain: The reason for which the vertical division of the eight-cell stage sea urchin results in a normal larvae, but the horizontal division leads to the development of abnormal larva.

Introduction: Cleavage is the division of zygote in a specified pattern. It occurs immediately after fertilization and results in formation of individual cells called blastomeres. Sea urchins belong to the class Echinodermata. They are globular and spiny creatures that are exclusively marine. They are characterized by radial and holoblastic cleavage.

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