@AliceD, wouldn't this question be right up your alley? biology.stackexchange.com/questions/37093

@AMR Thanks for this. I have seen this question and attempted an answer, but abandoned it. I'm more into sensory systems and I'm not familiar enough with the cardiovascular system to answer it. It's quite a good question.

@AliceD hello.. So how is your moving? Where are you going?

@Resonating I answered your iodine question.. I haven't fully described the info in the articles, but you can read them yourself... I hope the answer is helpful!

We survived an attack from cyber criminals.

@PlasmaHH - There is no reason to store something when it is freely available in the atmosphere. I don't understand your difficulty with the argument.

And organisms didn't keep it because it was waste. I don't know what to say more of it.

I'm repeating the comments and the answer.

You could choose to keep them if they are scarce. In that scenario, theoretically, some storage mechanism would have made sense. it doesn't make sense because 1) it's waste 2) it's abundant. Oxygen was used as final e- acceptor only when it became abundant. So yes, that argument is not in there.

I deliberately left it out as it is not necessary to answer the question.

@AliceD my difficulty with this is that it was not freely available in the atmosphere when the first organisms started with photosynthesis. So at first it was a scarce resource. So if you need it, you store it, if its truly waste, you don't care what happens with it. So the abundance (or not) has nothing to do with it being released, if it is truly a waste product that no one needs.

Additionally: Too much oxygen is toxic for us. We have very effective mechanisms to remove reactive oxygen species like the superoxide dismutase. Which is evolutionary very old.

Oxygen is like love :-)

@Chris maybe evolution tried to save us from this: youtube.com/watch?v=7NXfyCezUFk&feature=youtu.be&t=123 ^^

@PlasmaHH As far as I know, O2 was used as e- receptor only after it became abundant, as said

@AliceD ah ok, I read "O2 only comes in in the very last step" as the steps of the reaction, not that evolution came up with it after O2 was in the athmosphere

Hello all!

all: Hello

@Ϻ.Λ.Ʀ. thank you for repeating! lol

@Ϻ.Λ.Ʀ. how often do you come here on this site?

This one? Only this week.

@Ϻ.Λ.Ʀ. huh..

I didn't come here before.

@FaheemMitha you here? I was going to delete the meta post so I wanted you to take of the pin..

@Ϻ.Λ.Ʀ. it is a cool website...

Yes, not as cool as chem though.

@Ϻ.Λ.Ʀ. oh really? me flipping the crazy periodic table!

(ノಠ益ಠ)ノ彡┻━┻

@Ϻ.Λ.Ʀ. where do you anyway get those characters?

@TanMath Search Google for "unicode face characters".

@Ϻ.Λ.Ʀ. ok..

I am actually going to go.. @Ϻ.Λ.Ʀ. nice talking to you and helping in the TRE!

Hello everyone

Just a quick question: Do speeds respire aerobically or anaerobically?

My biology teacher told me that seeds respire anaerobically as well whereas in this document (biologyjunction.com/respiration%20of%20germinating%20seeds.pdf) only aerobic respiration is mentioned.

What? They're seeds.

Wait. Depends. They don't require oxygen to grow but also they respire it internally

Well, after they have seed leaves.

@Resonating Thanks for your response. There may have been just some misunderstanding, since I think I'm referring to seeds, not seedlings though

@Leuchte They don't respire very much at all while they're seed seeds, they only really start mtabolizing once they germinate

And after that they pretty rapidly develop green surfaces which produce oxygen

@Resonating I don't quite understand: are the seeds respiring at all or only photosynthesising?

Secondly, shouldn't the seeds respire before growing otherwise they would never be alive? See: uk.answers.yahoo.com/question/index?qid=20070126210726AAStAsA

@Leuchte Yes, both? Plants respire just like everything else: they just also run that process in reverse during the day

ugh yahoo answers

:)

"the site for fools" - Yahoo!

Seeds before germination respire, but they're dormant and consume almost no oxygen and almost no food

@Resonating Yes, and would that be aerobic or anaerobic respiration?

so the oxygen diffusing into the seed etc/oxygen remaining from when it was made is plenty

Let me put it this way: if it was anaerobic there'd be no way to tell.

but it's almost certainly aerobic even though there's so little of it the distinction is almost meaningless

What? It's definitely aerobic.

How would you know? They don't make lactate or ethanol or anything but if they did it would be in tiny amount and the second it germinated it would nearly instantly be respired normally

I understand now. The difference would be so small that it would best be left to your imagination. ;)

@Leuchte Yeah, like the electron could density around Na+ in NaF.

And one last question, shouldn't MRS GREN be MRS GREEN if we include evolution?

It would sound more...sensible

@Leuchte who is MRS GREEN?

@Resonating i.e. the basic principles for an organism to be classified as "living"

MRS GREN is full of crap, pardon my language.

Sponges or anaerobic geobacter clusters aren't dead, even if they never move except by growing

And what's the difference between 'growing' and 'reproduction' for a single-celled organism?

viruses similarly are considered "dead"

@Leuchte Only by pedants.

I have a straightforward rule about stuff being 'alive'. If it can be killed it was once alive.

In my opinion, there are conventional systems of classifying organisms, and no matter how faulty they are, they are still used as a way of understanding the world.

@Leuchte Yeah, no. I'm sure that's important for tests and things so you should learn it but a faulty taxonomy widely-used is still wrong. See the archaea for a great example. See Aristotle's classification of all the animals for a less-good example.

Long story short: arguing about whether viruses are 'alive' or 'dead' is like arguing what model year a handmade bicycle is

It's a perfectly reasonable property of some things being applied to stuff it doesn't apply to.

@Leuchte Sorry. the current definitions for what counts as 'life' get right up my nose.

@Resonating Then how would you classify an organism as "dead" or "alive"?

@Leuchte Mostly, I wouldn't bother. Practically, if it can be killed it is (or was) alive. You can kill viruses with heat, but you can't kill rocks or snowflakes. You can melt snowflakes but if you put the water back in the cloud it'll make snowflakes again. The line between 'alive' and 'dead' is not really a line, it's a continuum.

And there's the thesis that revolutionises the biology education industry in thousands of schools worldwide. ;)

Even big meaty things like humans are not really completely alive or completely dead. When you die your organs remain alive for a few hours, but your organs can be killed independently of you

@Leuchte We're well overdue such a revolution anyway.

And putting evolution into mrs gren would be even worse: Individual organisms don't evolve. You don't evolve, except in the sense that cancer is an evolutionary process and you probably have killed off several cancers already inside your body

Species evolve. humans only evolve if you view them as a colony of human cells that are constantly fighting for nutrients(whcih you can do, it's even a useful point of view) but on a larger level you haven't evolved at all since you were born.

I guess so :)

One of my favorite things about biology is a lot of words don't have absolute meanings.

The more you learn the more you realize that it's invariably too complicated and weird to be described with words like 'alive' or 'dead'

@TanMath Here.

@Leuchte plants do both aerobic respiration and photosynthesis.. Photosynthesis makes glucose not only for respiration but for other stuff like making cell walls, metabolites etc... That is why they do both...

@FaheemMitha can you unpin the message?

@TanMath Done.

@FaheemMitha thanks!