The vegetal pole of the zygote differs from the animal pole in that
A) the vegetal pole has a higher concentration of yolk.
B) the blastomeres originate only in the vegetal pole.
C) the posterior end of the embryo forms at the vegetal pole.
D) the vegetal pole cells undergo mitosis but not cytokinesis.
E) the polar bodies bud from this region.

Question

Quizplus · Accepted Answer

The vegetal pole has a higher concentration of yolk compared to the animal pole, which has less yolk and more cytoplasm. This difference in yolk concentration affects the development and differentiation of cells in each region.

Answer: C
 Although both the animal and vegetal poles give rise to cells during the early stages of development, the posterior end of the embryo is typically formed at the vegetal pole. This is because the vegetal pole has more yolk and nutrients that are important for establishing the body axis, while the animal pole has less yolk and more active cells that are important for early cleavage and differentiation.

Answer: E
 The polar bodies are small cells that are produced during meiosis in female gametes. They are typically formed at the animal pole of the zygote, rather than the vegetal pole. This is because the animal pole has more cytoplasm and active cells, which are needed for meiotic division and fertilization.

The Vegetal Pole of the Zygote Differs from the Animal