Why does some flowers close at night?

[user789653241]

My ds asked this question and we googled answers.
There were several,

1. To keep the pollen from getting moist so that it can be transferred easily by insect during the day.
   
2. To keep the flower safe from predators/damages during the night.
   
3. To keep them from frost.
   Maybe more, anyways, it was very interesting.
   
   But then came another question. How does plant detect temperature drop? I have googled it but couldn't find any good primary child friendly explanations.
   
   Anybody have any idea/good resources/ books/ sites explain this to 9 year old?

[mrz]

https://www.sciencedaily.com/releases/2010/01/100107132543.htm

[user789653241]

Thanks, mrz. But it is still too complicated for me!
Only thing I got was it's all about DNA.

Maybe this question is too complicated to explain without going into scientific explanation...

[Ferguson2]

This might help a bit, though it's not exactly what you wanted, but it might be a place to start:

www.s-cool.co.uk/gcse/biology/plant-growth/revise-it/plant-structure

Instead of Google, try GCSE or 'A' level links, or university, farming or horticultural web sites for technical information.

[sirfredfredgeorge]

"no idea, and the internet doesn't seem to be helping much, it seems to be not well understood, how do you think it could work?"

And then discuss how various things change with temperature that a plant might be able to use - changes in state - ice/water/steam, changes in air pressure with temperature.

Would be my approach.

But now I've actually had a look a bit more as I was interested, it seems the most up to date information is that the light detecting photo receptors that react to light during the day, reset themselves overnight, and how fast they reset themselves depends on the temperature. The pace of that change is what is recognised.

Pace of reaction change can probably be demonstrated and easily understood to a 9 year old with how quickly ice melts maybe?

[user789653241]

Thank you, Ferguson.
I'll have a look at the link.

Thank you, Sir.
I sort of get what it's all about, but try to explain to ds in English is very difficult for me. ( I wish I raised him in my native language as well.)
But I'll try your approach, and see how it goes.

We watched the you tube video on "how plant grow towards the light" while back, and it was really easy to understand even it used some scientific terms, but cannot remember the where i saw that from.
So kind of hoping someone may know something like that.

Hopefully in the near future, he can be able to do all the research by himself and don't need my help.

[Ferguson2]

Early this morning it dawned on me that THE place for information on plants is Kew Gardens, just west of London:

www.kew.org/kew-gardens

www.kew.org/science

www.kew.org/science/data-and-resources

(But I have tried to find out about flowers closing at night - without success! If you look at the Kew 'blogs' you may find it; I'll let you know if I find anything.)

[Etymology23]

So to try and explain what happens to the DNA from that first article (v abbreviated and simplified).

All your DNA is in your cell nucleus (basically a container for the DNA) in a big ball. You've got 2m of DNA in every cell, so to fit it in, it's wrapped round little proteins called histones.

In order to make proteins your cell has to "read" the DNA, and for that it has to be unwrapped off the histone proteins.

A change in temperate changes how tightly the DNA wraps around the histones (this could be for various reasons) and it changes how tightly some bits are wrapped more than others. This means different bits of the DNA can be "read", so different proteins are produced. Different proteins instruct your cells to do different things, so they can sense temperature like that.

(Your in this case being you the plant - humans have histones etc but I'm not sure that the temperature thing applies as we sense heat more quickly.)

[user789653241]

Thank you again, Ferguson.
I think he will love the kew site and of course the actual place. We should definitely have to plan to go there. I used to live near there years ago, but now we live so far away!

Thank you, Etymology, for great explanation. I don't think I can re-explain it to him verbally, so I will copy/paste it on notes and let him read it himself. I think he will get it with your explanation.

[Etymology23]

Glad to be of help - more complex than that in the detail obviously but cellular biology can be almost infinitely complex!