[jazoom]

My understanding (I'm a doctor but NOT an expert in this area) is that it usually is a long, difficult journey to the egg, and the chance of many getting there at exactly the same time is low. When a spermatozoan buries into the egg a reaction is caused which prevents other sperm from being able to penetrate.

An expert may be able to clarify, but I think this is the gist of it.

[munificent]

It's called the cortical reaction:

https://en.wikipedia.org/wiki/Cortical_reaction

[goodJobWalrus]

> When a spermatozoan buries into the egg a reaction is caused which prevents other sperm from being able to penetrate.

This is an explanation I was looking for. Thanks.

[gpvos]

I thought that was general knowledge. It certainly was part of the sexual education I got at school.

[gowld]

Sometimes, after many years, some people forget some of the irrelevant details of their education.

Do you remember all the steps in the ATP cycle?

[lugg]

"Not so irrelevant now is it"

Your teacher, maybe.

[denimnerd42]

same here.. unfortunately we can't assume reproduction was a fairly covered topic at schools across the US however.