B, a nucleus. Nuclei are membrane-bound organelles inside eukaryotic organisms. Eukaryotes are protists, fungi, plants, and animal cells. A bacteria is not a eukaryote, it is a prokaryote, so it does not have the membrane-bound structure of the nucleus.
Be careful, though, bacteria still have DNA. It is simply located in the center of the cell and is not encased in a membrane.
<span>This is the condition under which he would classify them as belonging to different species - the two salamanders cannot mate to produce a fertile offspring. If these two lizards belonged to the same species, they would normally be able to breed and give birth to a fertile new "child." However, given that they are not of the same species, they cannot do such a thing, which is why this scientist classified them that way.</span>
Depth, flow, temperature, and chemistry of overlying water
1 the atmosphere because gas is everywhere.
