[Campbell Biology P.1076] In human oogenesis, cytokinesis during meiosis is described as uneq... | Practice Question

In human oogenesis, cytokinesis during meiosis is described as unequal, with almost all cytoplasm segregated to a single daughter cell. What is the primary biological advantage of this unequal distribution for the resulting egg?

  • A: It ensures the rapid production of multiple eggs simultaneously.
  • B: It maximizes the amount of cytoplasm and nutrients available for the developing embryo after fertilization.
  • C: It minimizes the energy expenditure required for meiosis.
  • D: It allows for the formation of polar bodies that can develop into secondary eggs if needed.

Explanation

The unequal cytokinesis in oogenesis is a crucial evolutionary adaptation to ensure that the resulting egg oocyte receives the vast majority of the cytoplasm, organelles, and stored nutrients. This rich cytoplasmic content is essential to support the initial stages of embryonic development after fertilization, as the early embryo relies entirely on these maternal resources until it can implant and obtain nutrients from the mother. The smaller polar bodies receive minimal cytoplasm and degenerate, serving primarily to discard excess chromosomes while conserving resources for the egg.