Which is a shared feature of the embryonic development of chicks and placental mammals?
A) Cells migrate through a midline primitive groove during gastrulation.
B) The body of the embryo forms on top of a large yolk mass.
C) The hypoblast forms when cells of the blastodisc break free and form a continuous layer below the blastocoel.
D) Hensen's node forms the neural tube.
E) The hypoblast forms the body of the embryo.

Question

Quizplus · Accepted Answer

Both chicks and placental mammals undergo gastrulation with the migration of cells through a midline primitive groove to form the three germ layers. However, the other options are not shared features. In chicks, the body forms on top of a large yolk mass, while in placental mammals, the embryo develops in the uterus and is nourished by the placenta. The formation of the hypoblast differs between the two groups, with chicks forming it from cells breaking free from the blastodisc and mammals forming it from the inner cell mass. Hensen's node is a specific structure of the chick embryo that is not present in all mammalian embryos.

Which Is a Shared Feature of the Embryonic Development of Chicks