The answer is A. The diversity of species can occur in both plant kingdom and animal kingdom. And for the biological change, the sudden change over a single generation is called mutation. Only when the mutation is good for environment and the environment has changed, the mutation will be reserved and pass to the generations. Then <u>gradually</u> it will accounts the diversity of species.
It's the first one, prokaryotic cells don't have membrane bound organelles, including the nucleus
On a neutral state, the number of proton of a substance will be equal to the number of its electron (in this case, it has 15 electrons)
When three electrons are gained, the total number of electron will change to 18, this result in the substance became a negatively charged ion of 3-
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