Growth hormones and sunflowers

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Wookai
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Growth hormones and sunflowers

Post by Wookai » Mon Mar 28, 2005 7:23 pm

Hey!

I hope you can help me with this.
In my class we did an experiment and we had some sunflowers that we put some 'growth hormones' on so that the growth processes would happen faster. Here's a picture of what happened http://img42.exs.cx/img42/3334/sunflower0tf.png

It's the plant to the right which has the growth hormones on it.

Now our teacher has told us to explain what processes may have occured in the plant, which made it grow like it did.

I know that the growth processes has been affected by the hormones but I can't explain in detail.

Could anyone please help me.

ps. My english is not very good so I excuse any misspellings.

Thanks in advance

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mith
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Post by mith » Mon Mar 28, 2005 8:51 pm

is the plant dead? Is the stem soft?
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Wookai
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Post by Wookai » Mon Mar 28, 2005 10:14 pm

No, the plant isn't dead. I don't remember if the stilk was hard or soft.

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Post by biostudent84 » Tue Mar 29, 2005 4:42 am

The growth hormone caused upward growth, but not sideways growth. My apologies for forgetting the terms here. My schooling in this is not sufficient...but I do remember this much.

When plants grow, they need separate "actvators" to cause different types of growth. Just as your body grows both larger and taller at different times, so do plants. There are actual terms for sideways growth and upward growth...but I cannot remember. My professor sped through plant development because she doesn't like them...

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guessing

Post by 2810712 » Tue Mar 29, 2005 5:19 am

Which hormone [ from which chemical group/s]eg.auxins,cytokinins,GAAs etc Or a combination ,in what concentrations then ? It matters, . Some of them induce increase in cell no. and elongation of cells, this helps to get theirselves growing in the direction of sunlight by bending[ elongation facilitates bending]
From the picture plant seems to be alive and stem seems to be soft. So, one reasone may be-
As you have put excess of that hormone it has bent more than required-just guessing .

Ask u'r teacher , and confirm this for me please, i'm curious.
Also, why did you choose sunflower ??? Selection of sunflower may be a hint for the students .

thanks,

hrushikesh

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MrMistery
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Post by MrMistery » Tue Mar 29, 2005 6:48 pm

From how that plant looks, my best guess would be an overdose of auxine+cytokinine. It depends very much on what hormones have been used, but, with only that picture to guide me, that is most specific i can be.
Hope it helps

PS: Do you need to present details of what happened too?
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

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mith
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Post by mith » Tue Mar 29, 2005 8:32 pm

Have you checked the roots?
Living one day at a time;
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Wookai
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Post by Wookai » Wed Mar 30, 2005 3:50 pm

The hormone we used was auxin, but I don't know in which concentrations.

Btw. we didn't put the hormone on the whole stem, but only on one side of it. Because our theory was that if we put the growth hormone on only one side the cells, on that side would grow faster and the plant would bend.

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Post by MrMistery » Wed Mar 30, 2005 6:06 pm

Is the stem soft or hard? If the stem is still hard then it means that is was an overdose. If it is soft, then the plant reacted strangely to the auxin
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

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Post by soltan » Thu Jul 21, 2005 11:53 am

sunflower was a hint. i'm trying to work this out myself so i won't try to explian what is going on but the best summary of what is happening that i've found is on this page specificly Phototropism.
http://www.biology-online.org/3/5_plant_hormones.htm

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Post by mothorc » Thu Jul 21, 2005 12:51 pm

we can't explain anything if we don't know which hormone you used, how did you do, and concentration of hormone. But with your sunflower, there are two things to see:
1- The concentration can be low and auxin make some special cell longer (properties of auxin) so the plant become solf but not die.
2- The concentration is high (but not too high) and auxin become an inhibitor, but the plant still alive . (like 2,4-D used in Vietnam)

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