Thursday, January 1, 2009

so i suddenly became curious halfway thru choinging hw n decided to search for this:
why do seeds know which way up to grow?
& then i found the answer which was this:
the underlying force for growth is gravity.
& also many other possible factors like these:
 -Magnetism: some bacteria can use magnetism to indicate way is up (although this would not be possible around the magnetic equator), but I am not sure that plants would use the same.
-Heat: cold nights and warm days are up, while a more steady temperature would be down. I suspect the differential is not that great over the short height of the average seed to make this a plausible mechanism.
-Light: especially in seed that are not too deep in the ground, there must be some light getting through from the surface.
-Water: they may not actually care that much as to which way is up, but care more where they can get their next drink, so they smell water from the water table below.

source:http://www.thenakedscientists.com/forum/index.php?topic=9181.msg211460;boardseen

& plus,i came across other interesting facts like this:

The work Of Professor H.T.Hammel:EVERYTHING YOU WERE TAUGHT ABOUT OSMOSIS IS WRONG.

Osmosis is the reason that a fresh water fish placed in the ocean desiccates and dies. Osmosis is the reason that blisters form on fiberglass boat hulls. Osmosis is how waste products of metabolism enter and leave the blood stream. Osmosis determines how you, me and every living thing lives and dies. One would think that a civilization that spends billions of dollars every year on medical research would understand something as basic as osmosis. Wrong, wrong, wrong.Source: http://www.yarbroughlaw.com/Osmosis.htm

Or what about Root Pressure? Roots can squeeze water to the tops of trees? You what?. ROFLMAO. Sorry but every time I read about root pressure it makes me cringe.

Or maybe capillary action? In other words, a tree is a giant sponge capable of blotting water from below ground level to heights in excess of a hundred metres at flow rates that can exceeding a thousand gallons of water a day in a single tree.

Does the cohesion tension theory suck? How can leaves create suction when there are pores in them open to the air? Is it not like trying to suck water through a straw with holes in it?

source:http://www.thenakedscientists.com/forum/index.php?PHPSESSID=49d23a445c3bc01743d28fee9f50f9e7&topic=1982.0

bye bye,back to choinging hw.



you're exactly my brand of heroine.3:45 AM