Practice question

Oogenesis features highly asymmetric cytokinesis preserving ooplasmic resources for embryogenesis. During meiosis I and II, division planes are peripheral, extruding diminutive cells called polar bodies containing excess haploid chromatin sets with minimal cytoplasm. First polar body formed after meiosis I may further divide. Polar bodies degenerate without developmental role, allowing preferential retention of mitochondria, mRNAs and nutrients in secondary oocyte and later ovum. This conservative allocation contrasts with symmetric spermatogenesis producing four functional gametes from one spermatocyte efficiently conserving maternal reserves for early embryonic development, genome activation and cleavage support.