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!
the sun gives all living things there energy
Explanation: Survivorship curves fit three types. A Type I curve shows a low death rate in early and middle life but the death rate increases steeply in old age. A Type II curve shows a death rate is more constant throughout the lifetime of the species.
Answer:
where your baby is at least 37 weeks
Explanation:
In cases where your baby is at least 37 weeks, current research suggests that it may be safe to wait 48 hours (and sometimes longer) for labor to start on its own. (But your caregiver may have a different protocol, like 24 hours.)
The correct answer is (a.) a mutation of the hemoglobin allowing better oxygen-carrying capacity. The mutation of the hemoglobin that allows a better oxygen-carrying capacity would be the most beneficial to an elephant and its descendants.
