What definition is used to determine the moment of death for a plant as an organism?
That's an interesting question. Why do you ask?
My wife was talking about "vegan" dietary principles the other day. One of which is something like they must only eat living organic foods. We're both omnivores, it was just a little idle conversation over dinner one night.
Anyway it just made me wonder how they know a plant is still "alive"? Which led to wondering how death is determined for plants as organisms.
If a plant (or a piece of one) undergoes respiration (oxygen uptake, carbon dioxide evolution in the dark) at room temperature, then it's alive.
However, most dead plants are covered with microorganisms that are alive, consuming the dead plant, and respire, too. Complicates things from a practical point of view.
Great dinner conversation, and food for thought..
My concept of plant death is when ALL its cells die. Up to that point a plant could very well live indefinately (with a little help), by http://plantphys.info/Plants_Human/vegprop/vegpropa.html [Broken] by cuttings, bud grafting, tissue culture and other techniques
So certainly fresh fruits and vegetables are very much alive. As are fresh seeds and nuts. :tongue2:
Ahh, so then it's how I suspected it was. The moment of "death" for a plant, at the organism level, can't really be determined as easily as for animals.
Yep, interesting stuff...thanks for the replies.
If it's dried up, slimy with rot, or turned brown, it's probably safe to call it "dead." Cutting the plant from the roots and removing it from water might be similar to stopping circulation in animals, but as you know if you stick the cut end in water quickly enough, it will continue living for much longer.
One thought that comes to mind is whether this concern arises from the need to eat vegetables while they are fresh enough to have good vitamin content? Once you harvest the plants, they start losing nutrients because they are no longer receiving all their food sources to continue storing nutrients (i.e., from the soil). Even a seed is surviving off stored nutrients, and can only do that for so long, which is part of why older seeds will reach a time when they will no longer be able to germinate and will eventually start rotting.
Though, even for animals, death at a cellular level is more gradual too. We just have a definition for clinical death, but that doesn't mean that all organ systems have already died, or else there would be no possibility for organ transplants to work.
I think you're right about the vegan reasoning for recommending to eat only living plants. The vegans would probably say something non-scientific like "living foods have more life force" as opposed to the nuts and bolts description of how plants decay after being harvested though.
As for animals my wife also said something about why they think it's bad to eat. The claim there is that a "death hormone" is released in animals in cases of mortal wounds that instructs all cells to die off rapidly. The downside to this in the vegan view is that consuming some of the dead flesh (cooked or not) causes one to digest some of the "death hormone" that was released, even though in trace quantities.
Surprisingly I saw something on an investigative TV show that confirmed it somewhat a while back. The show I saw, I think it was 20/20, reported on a crime where a doctor had used some of this stuff to kill someone. Apparently it was/is readily availble to those working in certain medical fields.
I have never heard of anything called a "death hormone" so have no idea what that even might refer to, or if it's entirely fictitious. If it's some sort of protein/enzyme, then it'll just be digested like any other proteins.
I think maybe Reailty is referring to some physiological reaction to trauma - like shock.
How about this ?--we apply to all organisms (plant, animal, microbe, etc.). Death is the moment when the collective selfish genes of the organism lose ability to transfer information over time (hopefully not too philosophical).
Selfish genes of the organism??
Transfer information over time??
I had the same questions.
By your definition someone is dead when they have taken a sterilization or vasectomy procedure.
Final end of all the processes involving the photosyntesis?
So plants die at night?
To me something is dead when it cannot be brought alive anymore, when it starts to disintegrate. This is a biochemical definition and is hard to define. As an organism a plant dies when it runs out of all nutrients and is unable to metabolize.
No, the "collective selfish genes" (sensu Dawkins), not the gametes--think stem cells. A single somatic cell of my body maintains the ability to transfer information over time no matter what you do to my gametes --until such time that I reach a state called "lack of life" = "non ability of collective selfish genes to transfer information" = "death".
Specifiy collective selfish genes..
Not if they respire and release carbon dioxide.
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