This is equivalent to nick translation, except that the new DNA replaces a stretch of RNA rather than a segment of DNA.

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#Id: 7612

#Unit 5. Developmental Biology

A second slow block to polyspermy comes from the so-called zinc spark, the release of billions of zinc ions that is induced by the entry of the first sperm These released zinc ions are bind to the zona pellucida

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#Id: 7613

#Unit 5. Developmental Biology

Acrosomal enzymes (acrosin and MMP2) as well as the enzymes that help establish capacitation, are inhibited by zinc, the accumulation of zinc on the zona pellucida and in the surrounding cumulus form a “zinc shield” that prevents further sperm entry

TLS Online TPP Program

#Id: 7614

#Unit 5. Developmental Biology

Mechanisms of Egg Activation

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#Id: 962

#Unit 5. Developmental Biology

Cleavage type- Unequal radial holoblastic cleavage

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#Id: 963

#Unit 5. Developmental Biology

The point of sperm entry -determines dorsal-ventral axis

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#Id: 964

#Unit 5. Developmental Biology

In the amphibian embryo, C3a functions as a short-range chemoattractant to guide epiboly in ectodermal cells.