Re: How does cigarette affect the way the plant ivy grows?

I assume that you mean cigarette smoke's effect on plant growth.  Grinding 
up cigarettes and adding them to the soil is different story.  

I honestly don't believe that there is much effect of reasonable doses of 
cigarette smoke on plants.  This is not my area of research and I do not 
know of research in this area.  The smoke itself is particulate matter that 
will accumulate on the surface of plants.  As it does, the plants will have 
more and more trouble breathing.  The pores (stoma) on the leaf surface can 
become clogged with things like dusts.  The tars in smoke will also block 
these pores.  This coating may also make protective chemicals produced by 
the plant less effective.  Thus, resistance to disease may be reduced, 
although I have not seen any studies that address this.  Cigarette smoke is 
also rich in carbon monoxide and low in oxygen.  The plants may have 
difficulty living in an atmosphere very rich in carbon monoxide, as it is 
reactive with some enzymes.

Another issue is that of genetic mutation.  Some of the chemicals in 
cigarette smoke cause cancer in humans.  This is because the chemicals 
cause mutations (changes) in the DNA of the cell.  As you may know, the 
sequence or order of the bases of DNA carry information.  This information 
is used to make proteins that perform the chemistry of life.  If the 
information is changed by mutations that change the order of the bases, 
then a different protein is made.  Usually mutations cause changes that are 
bad to the protein and it won't work anymore.  This could cause that cell 
to die.  If it was in a critical gene in a seed, then the seed may not grow 
to become a plant.  Plants don't have the cancer genes that animal cells 
carry and wouldn't have cancer genes (oncogenes) turned on by these 
mutations.

These are the only effects that I can think of right now.  But again, this 
is not my area of research.  If you were to run an experiment where plants 
were exposed to cigarette smoke, I doubt that you would be able to measure 
any change in growth rate.  Perhaps if the amount of smoke was very high, 
you might see the effects, but even here I doubt that you would actually be 
able to measure these effects by measuring growth. Unless there was so much 
smoke that it blocked out the light significantly.  Then you would see an 
indirect effect.