It would be the nuclear membrane
Answer:
I think d . brain must be the ans
<span>The experimental evidence that leads </span><span>scientists to believe that only quantized electronic energy states exist in atoms </span>was the Niels Bohr experiment on Hydrogen gas. The quantized model for electron orbits in atoms that effectively explained the spectroscopic behavior of the atoms. Each line in the spectrum corresponds to one exact frequency of light emitted by the atom.
Answer: A) Tropical regions have more available niches into which new species can occupy.
Explanation: USATestPrep
Background extinction refers to the normal extinction rate. These are species that go extinct simply because not all life can be sustained on Earth and some species simply cannot survive. Mass extinction is a widespread event that wipes out the majority (over 50%) of living plants and animals.