The correct sequence of events in the development of humans and other mammals is ________.
A) cleavage, gastrulation, organogenesis, and then formation of a blastula
B) gastrulation, formation of a blastula, cleavage, and then organogenesis
C) cleavage, formation of a blastula, gastrulation, and then organogenesis
D) gastrulation, organogenesis, formation of a blastula, and then cleavage

Question

Quizplus · Accepted Answer

The correct sequence of events in the development of humans and other mammals is cleavage, formation of a blastula, gastrulation, and then organogenesis. This is because after fertilization, the zygote undergoes a series of rapid cell divisions called cleavage, resulting in the formation of a multicellular structure known as a blastula. Gastrulation then follows, during which the cells of the blastula reorganize to form three germ layers - the endoderm, mesoderm, and ectoderm. Finally, organogenesis occurs as the germ layers differentiate and give rise to various organs and tissues. Option A, B, and D are incorrect as they do not follow this order of events.

The Correct Sequence of Events in the Development of Humans