Chloroplast, Mitochondria, Nucleus

[seders99]

So when asked to rank these as most important to "life" on planet earth this is what I got:

Chloroplast
Mitochondria
Nucleus

Now to explain in detail and specifically why this is:

Life is only possible by a constant cycle of energy. Chloroplast is most important because it is the sight of photosynthesis and what captures energy from the sun.

Mitochondria is next important because it is the power plant for cells and it makes energy into the ATP form.

The nucleus is where genetic materials are stored and DNA/RNA are synthesized.

So, hows that for an answer. My professor is very strict so I wonder if my answer is detailed and specific enough. Any suggestions? THANKS

[plasmodesmata11]

This seems good. All of them are important, but mitochondria and chloroplasts were, at one time, thought to be independent. Therefore, the ordering works if you apply it to life as time progressed. Today, though, I think they're all important; cells couldn't function without them. But seeing as that's not an answer, I'd say you're right.

[futurezoologist]

Your professor may be looking for: "they are all equally important because without any one of them life would be impossible blah blah etc.", that would be my answer anyway, with any one of those gone we would not exist.

[MrMistery]

life is possible without any of them (cyanobacteria...)

[alextemplet]

This sounds like the sort of question that would depend not on what your answer is, but on how well you can explain your thinking and reasoning. Some professors love to test for that sort of thing.

[biohazard]

For example, there are chemosynthetic bacteria living hundreds of meters below the Earth's surface, which do not depend on energy from photosynthesis as we surface dwellers do. So life would go on even if there were no chloroplasts, mitochondria or nuclei.

However, I'd probably go for the order 1) chloroplast, 2) mitochondrium, and 3) nucleus if I had to answer that question. Photosynthesis supports the vast majority of all life here, and mitochondria power up much of it. And nucleus, well, life would probably do without it as well, but it comes handy when packing your chromosomes :P

[JorgeLobo]

They all presume eukaryotic cell structure. As MrMystery suggested, maybe none of them

[seders99]

WONDERFUL!! Thanks for all the responses. My test is tomorrow so Ill let you know how I do. My professor is not the ordinary. Its just a community college but he "talks, not teaches" as though its a post graduate school. THANKS Again..

[futurezoologist]

yes well i suppose it depends on what he meant by 'life', i took it as human life.

[biohazard]

Hmmh. If we would only talk about human life, then I guess in theory you could artificially synthetize amino acids, proteins, sugars and lipids from inorganic precursors (or existing organic matter), so human life could that way survive even without chloroplasts. Of course not the 6 billion or so of us, but some human life nonetheless. But without mitochondria we'd be dead instantly, and we need our nuclei as well.

But obviously seders99 meant "life" as in life in general on this planet, so I guess the original answer stands: prokaryotic life wouldn't necessarily need any of the aforementioned organelles, and eukaryotic life would :)

[seders99]

So I got my test back and received 8/10 for that question. Which is good. But he said that to be accurate it needs to be looked at universally. Because I specifically mentioned plants and humans. And thats where I went wrong. THANKS for all the adivce.

[MrMistery]

so you should have mentioned cyanobacteria dude!
Anyway, glad you found the forum useful