paul

or does one DNA molecule = all the chromosomes, ie, all the genetic material in our cells?

thanks a lot guys. alien, you mentioned diamond and graphite as being macromolecules; is DNA also a macromolecule? also, you said momomers don't have to be organic, but usually are - then you said sulfur can form chains; do you mean compounds containing sulfur - or just sulfur (because i thought monomers were compounds linked together, as opposed to "single element molecules")? one last question; i've now read many definitions of monomers; one says, "...linked to other identical molecules." ; so a monomer is a relatively small chain of IDENTICAL molecules? it can't be a number of different molecules linked together?

i've heard monomers described as, "simple organic compounds which can link with other compounds to form polymers" Q. are monomers always organic? and does organic always mean containing carbon? Q. who simple does a molecule/compound have to be to be labelled 'simple'? Q. how large/complex does one have to be to be called a macromolecule?

i've been reading about phenomena such as; relative atomic mass electronegativity density ionisation energies melting point atomic radius electron affinity boiling point Q. which of these are PHYSICAL properties? and which are CHEMICAL properties? Q. what is the difference between a physical property and a chemical property?

thanks mokele. i asked this question on yahoo answers and was surprised at the confusion my question caused. hardly anyone (including graduates) seemed to know what i meant by 'kingdoms'. isn't 'kingdoms' standard taxonomy? also, the one person who wasn't confused reckoned they evolved in the following order; archaea; bacteria; protists; fungi; plants; animals; any thoughts?

in which order did they evolve?

i have read a wiki article on this, but i'm looking for further opinions. also, if nasal breathing is superior, why is it?

thanks mokele, but it was a full rupture. there is debate as to whether surgery is advisable even with full ruptures (as it can lead to infection, and conservative treatment is almost as effective). my leg's fine. i'm curious though, about the 'knitting' process; what actually takes place? do the cells themselves rupture as a result of the accident? or is it a break in the bond between cells? how do cells bond together anyway? and how do they 're-bond' following rupture?

i ruptured my achilles earlier this year. surgery was discouraged. my leg was put in plaster (initially in the equinus position) for 11 weeks. it is now healed. but what actually happened? how did the two ends 'knit' together (if 'knit' is the correct word?)?

i know it can be frozen to be used in cooking at a later date; but can it be frozen to be drunk at a later date? how would the alcohol content be affected by the freezing process? and what about flavour etc?

thanks again (does anyone know the answer to my last question ^^^about the individual skin cell, and the types of cell (out of the 200 or so different types) that could survive as single entities outside the body?)

ie, is it unlike the muscular system in that it can't move unless pulled and pushed by muscles? also, are there neurons running throughout the bone tissue? and if so, what is their function (assuming that the brain can't send a signal to them to instruct them to move - in the way it can with muscles)?

when a doctor taps your knee to test your reflex, a signal is sent from the neurons in the knee to the spinal cord; does a signal then go straight back to the knee from the spinal cord; or does it first go from the spinal cord to the brain (to be 'processed') befor a signal goes from the brain to the knee?

thanks. really helpful. npts2020 mentioned skin grafts; i'm guessing several skin cells (ie, a piece of tissue, a piece of skin) are the starting point for this - rather than one individual cell. but could literally one individual skin cell be taken from someone, put in a petrie dish, 'fed' and 'cared for', and survive and propagate? (also, i've learned recently that we consist of around 75 trillion cells, and there are around 200 different types of cell; how many of the 200 types of cell could survive as a single cell in a dish?)

could a cell (say, a muscle cell) be taken from the body and put in a petrie dish and kept alive in the dish?