Organisms exchange molecules with their environment to obtain the materials needed for growth and reproduction. discuss factors that affect the rate of exchange of these molecules with the organism's environment.

Concentration gradients are the key to effortlessly getting what you want.  

think of it this way if you were at the top of the hill and pushed a log and then sat by and watched the log roll down the hill.  you didn't have to put much of any energy into doing this it just happened naturally.  cells and organisms do this all the time.  

another example is if I put food coloring in a gallon of water.  the gallon would gradually change colors.  this is a process called defusion and cells use this to their advantage.  our body uses this to its advantage.  when we breathe we are using defusion at its best. 

my last and final example is a fart.  think about it if you fart you can smell it right away and its probably per stinky but as time passes you can no longer smell the fart. and that is because the order has spread its self so thin that you can no longer smell it.  

so organisms can use defusion and cosmos's to their advantage and they can use different types of transport such as active transport and passive transport 

active transport is where the cell or organisms spend energy to do work.  and work could be any thing from moving to getting food and so on.  

We can use solar powered cars or ride bikes instead of cars that burn fossil fuels

Carbon-14 has a half-life of 5,730 years and most igneous rock is older than that.