Would depend on the bike, but a few hundred.
seat/handlebars
The bearings don't need friction, but everything else does. It there wasn't any friction it'd be impossible to bolt anything together.
The answer is Seat and Handle Bar
Yes. If you buy a bicycle from wal-mart, it will come with all the required parts, as tires, already mounted.
Any such list must be subjective - there is no authorized ranking. I suggest: Guernica The Girls from Avignon The Old Guitarist Self-Portrait (1907) Paulo as Harlequin Weeping Woman Bull's Head (made from bicycle parts)
No, that is why there are so many parts.
Havoc is a brand of bicycle parts and helmets.
The bicycle is not a simple machine, there are too many interacting moving parts.
There are too many parts, and to many versions of each part for it to be possible to give an answer here.
Bicycle parts are very rarely specific to a certain make & model. Functionally identical replacement parts will be available from almost any bicycle shop.
Bicycle parts can be seen at many stores that sell bikes like Wal-Mart , best buy , and a sports store. Here are a couple of sites for you to look at www.lonelyplanet.com/thorntree/thread.jspa?threadID=2172130 , and www.qbp.com , and www.slanecycles.com .
Generic parts like pedals, cranks and chain you can get from any bike store. Proprietary parts you have to get from the manufacturer.
Nowadays, you can buy almost anything on line. Simply search the internet and have a browse through the many websites offering bicycle parts.
A person who repair bikes is a bicycle mechanic. A shop that handles bikes is a bicycle shop or a bicycle store.
Most bicycle parts are actually generic, so they should be available from just about any bicycle store. Anything real special, then you have to hunt for it at ebay, craigslist and similar.
The brakes and the tire treads.
You can buy cheap bicycle parts from the retailer Pricepoint.com. They offer accessories, frames and complete bikes at up to 80% discount from retail prices.