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

TLS Online TPP Program

#Id: 554

#Unit 2. Cellular Organization

Vegetative cells begin sporulation when a key nutrient- carbon or nitrogen source becomes scarce.

TLS Online TPP Program

#Id: 2550

#Unit 13. Methods in Biology

Addition of certain proteins, such as, bovine serum albumin enhances efficiency by protecting the DNA polymerase and by binding to PCR inhibitors. 

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#Id: 6328

#Unit 8. Inheritance Biology

XX-XO SEX DETERMINATION

The mechanism of sex determination in the grasshoppers studied by McClung

TLS Online TPP Program

#Id: 3643

#Unit 3. Fundamental Processes

The Class II synthetases lack the foregoing sequences but have three other sequences in common.

TLS Online TPP Program

#Id: 5492

#Unit 10. Ecological Principles