The body's axis of development is determined by the
A) blastomeres.
B) epiblast.
C) notochord.
D) primitive streak.

Question

Quizplus · Accepted Answer

The notochord is a structure that first appears during embryonic development and extends along the future longitudinal axis of the body. This structure influences the formation and positioning of other structures, such as the spinal cord and somites, which later give rise to the musculoskeletal system. Therefore, the notochord determines the body's axis of development. A) Blastomeres are the cells resulting from the cleavage of the zygote. They do not determine the body's axis of development. B) The epiblast is the inner layer of cells in the blastocyst stage of embryonic development. While it contributes to the formation of the embryo, it does not determine the body's axis of development. D) The primitive streak is a groove that forms on the surface of the epiblast and is important for establishing the three germ layers of the embryo, but it does not determine the body's axis of development.

The Body's Axis of Development Is Determined by the