General > Biology

Cell Wall/ Cellulose / Vacuole / Chloroplast

<< < (2/5) > >>

Numsgil:
You're still examining effects and not the causes.

All a plant theoretically needs is CO2, water, and light.  Everything else, the nutrients, etc, are neat little tricks plants have learned along the way.  Anyway, a plant could always just evolve a mouth, eat some dirt, digest what it likes in the dirt, and defecate the rest.

Worms do this.  It's obviously possible.

Animals obviously evolved to move.  Common logic tells you if the choice is only between moving and not moving, you'd learn to move in response to being eaten.

Plants don't move because they have strong, hard, rigid cell walls.  WHy do plants have cell walls?  It helps to control the turgor pressure (osmotic pressure) of their vacuoles.

Well, why do plants have vacuoles?  Animals seem to get by just fine without them, so they obviously have some relationship with things that animals don't have.  Probably chloroplasts.

You can photosynthesize just as easily moving as not, so obiously plants are not rooted/have cell walls because they need them for photosynthesis.  There must be something about photosynthesis with chloroplasts that demand a large vacuole, which then in turn directs a number of consequences.

PurpleYouko:
Maybe the evolution of the vacuoles and chloroplasts simultaneously was simply chance.

Do primitive algaes have vacuoles?

shvarz:
Yeast have vacuoles.  They don't do photosynthesis.

Griz:

--- Quote ---Maybe the evolution of the vacuoles and chloroplasts simultaneously was simply chance.
--- End quote ---
there ya go.
evolution has very little to do which entities making 'choices'.
evolution exists independent of anything making choices ...
gypsy moths didn't 'choose' to mimic the bark of the trees they live on ...
they exist and continue to exist because for whatever reason ...
some mutation resulted in them matching the bark ...
and THAT is what increased their chances of survival and propagation.
evolution works because:
what works lives and continues ...
what doesn't work dies and doesn't.
period.
it has little to do with decision making or control ...
that's just we humans thinking we are somehow the end
product and crowning achievment of evolution and life.
pah!
we are only one tiny part of life ...
no more, no less ...
the web of life and it's diversity is awesome ...
compared to we puny little beings.
we are tiny little specks in the universe ...
and certainly don't seem to know our place ...
we still think it is all about us. ;)
life, evolution, nature ... is indifferent ...
it isn't complicated, it's simple ...
what works continues ...
what doesn't ends.
who knows ...
earth may have a few billion years left ....
perhaps some intellegent life form may yet evolve.
[perhaps you can tell ...
I'm not all that impressed with humans ...
I think we've made rather a mess of things.] :D

jijimuge:
all things and events are mutually interpenetrating and interdependant.

~griz~

Numsgil:
Perhaps choice is too strong a word.

Basically everything an organism has is either an adaptation or a result of an adaptation.

We have chins, for example, because of the way our jaws have evolved, not because chins are a magnificent adaptation.

Chins are the effect, jaws the decision.
Did a little thinking.  Could it be that the large vacuoles allow a plant cell to have more surface area than otherwise without a huge metabolic cost?

Vacuoles are basically just a large sac of water, so that would support such a conclusion.

The larger surface area is then surrounded by chloroplasts.  The result is a much increased ability to photosynthesize.

That the woody parts of plants have vacuoles too, even though they don't photosynthesize could just be that cells have a hard time unevolving something once it's evolved.  Basically the woody parts of plants must follow the path of their leafy forefathers.

That makes alot of sense, someone tell me if something in my reasoning is off...

Navigation

[0] Message Index

[#] Next page

[*] Previous page