Hi there!
A prezygotic isolating mechanism is a mechanism that causes something to happen, not allowing the organisms to breed before fertilization. I'll explain each one for you.
A - That is postzygotic because the organisms were not stopped before fertilization. The result is a sterile organism.
B - Again, that is postzygotic because the organism was produced.
C - This is prezygotic! The sperm dying shows that something is in action to prevent fertilization, meaning that it cannot happen.
D - Fertilization was successful, so it is postzygotic.
ANSWER:
C - the sperm dies when it reaches the female tract
If you need help with any more problems, feel free to message me and I'd be more than happy to help you work through them and provide explanations.
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!
Fossil fuel power burn carbon fuels such a coil,oil or gas to generate that drives large turbines that produces electricity by burning carbon fuel they produce large amount carbon dioxide.
The answer is B. This is because baby dolphins, when born, can't really comprehend a lot of things yet, so they, and the more adult dolphins there, try to get to the surface of the ocean to take a breath. :D I hope I helped!
The molecule will enter the cell using a channel protein.