Answer:
Some have lifelong relationships with other organisms, called symbiotic relationships. There are three different types of symbiotic relationships: mutualism, commensalism, and parasitism. Commensalism: only one species benefits while the other is neither helped nor harmed
Answer:
The main distinction between bacteria and eukaryotes is that bacteria lack a genuine nucleus and membrane-bound organelles, whereas eukaryotes have both.
Explanation:
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Carbon dioxide should be the answer considering its a huge focal point in our climate today and how it affects it.
If you have a disease like this, it most likely affects your immune system, or your ability to fight off bacteria (that's what your white blood cells do). A person with aids most likely was sick with something simple that evolved into pneumonia because the white blood cell count was low (their immune system was down).
The correct answer here is "cell membrane". Generally it makes sure that nothing enters or leaves the cell, except by its highly guarded "gates", such as ion channels, that let some particles through - but they're very picky about whom to let in!