After the fertilization of a sea urchin egg, the influx of which ion prevents polyspermy?Multiple choice question.SodiumChlorideCalciumPotassium

Analyzing the Question

1. Understanding Polyspermy: Polyspermy refers to the fertilization of an egg by more than one sperm cell, which can result in abnormal development.
2. Role of Ions in Sea Urchin Fertilization: Upon fertilization, specific ions play a crucial role in preventing polyspermy.

Relevant Concepts

1. Calcium Ions (Ca²⁺): In sea urchins, the influx of calcium ions is a key mechanism in the fertilization process.
2. Cortical Reaction: The release of calcium ions triggers the cortical granule exocytosis, leading to changes in the egg membrane and formation of a fertilization envelope.

Conclusion

Based on the role of ions in the fertilization of a sea urchin egg, the influx of Calcium ions is what prevents polyspermy.

Final Answer

Calcium is the ion that prevents polyspermy after the fertilization of a sea urchin egg.