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!
Biogeographic isolation means that a population is separated and there are two populations in two different areas. As normal mutations take place, but certain mutations will be seen as advantageous in the different areas. For. Example if an area had taller trees the organism may develop a gene to grow taller. This is then passed down to offspring. This process continues so that more gene differences are created within the species and the frequency of these alleles increased: leading to two different species developing-
Answer:
The correct answer is B) lives in trees
Explanation:
Hope this helps :)
Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
The question is incomplete as it does not have the options which are:
artificial
enhanced natural
extraterrestrial
manmade
Answer:
Enhanced natural resources
Explanation:
Natural resources are the resources used by the humans for survival present in the environment or provided by the surrounding environment.The natural resources includes the wood, gas, air, water and other substances.
The substances which emits harmful radiations like radium, thorium, uranium are known as radioactive isotopes.
When these ionizing radiation emitting natural substances increases in the environment due to human activities like the particle accelerators, X-rays and other methods which produces these substances then these substances are refereed to as the enhanced natural substances.
Thus, Enhanced natural resources is the correct answer.
