Draft:How amount and distribution of yolk affect cleavage

  • Comment: Sorry, but this is not written as an encyclopaedia article, it's more in the style of Q&A. In any case, such a fact in isolation is not enough to justify an article; please incorporate this instead into one of the existing articles linked to in this draft. DoubleGrazing (talk) 09:09, 31 October 2024 (UTC)

Why does the position and amount of yolk matter for cleavage?

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In some organisms where fertilization occurs inside the female reproductive system, they have a small amount of yolk, leading to a holoblastic cleavage. Then again, cells with a large yolk undergo meroblastic cleavage while the resulting daughter cells remain attached to each other. Conversely, the presence of yolk accelerates early development. Those organisms with a large amount of yolk have their fertilization occurring outside the female body, leading to meroblastic or unequal cleavage. A large amount of yolk serves to nourish the cells.

Isolecithal eggs have only a small amount of yolk evenly distributed throughout the cytoplasm, so they should cleave more. In some cases, the cleavage furrow does not completely divide the cytoplasm of the egg at each cell division.

References

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  1. https://biocyclopedia.com/index/general_zoology/how_amount_and_distribution_of_yolk_affect_cleavage.php.
  2.  https://mhhe.com/hickmanipz16e, Integrated Principles of Zoology ,Sixteenth; Edition Hickman Roberts, Keen Eisenhour, Larson J' Anson. Chapter Eight