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!
Answer:
The feeding relationships among the species in a community determine the community's trophic structure. C)
Answer:
Lymphocyte ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎
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︎ ︎ ︎︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎
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︎ ︎ ︎︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎ ︎
The correct answer is D. Salt water.
Explanation
The hydrosphere is the system that groups all the waters of the earth that include oceans, seas, rivers, lakes, lagoons, frozen waters like ice and snow, among others. The water of the earth can be classified between salt water and freshwater, within the first group we find the oceans and the seas that represent two thirds of the total water of the earth, that is, 93 percent of the total water of the earth, a figure close to 1 370 323 000km³; the rest of the water is fresh and consists of rivers, lakes, lagoons, streams, groundwater, and glaciers. So, the correct answer is D. Salt water
I think b. Proteins are polymers of amino acids is the correct answer
