I can take mongodb data backup but I am not sure about mongodb schama backup. Is there any way to take dump of MONGODB schema only not the data ?
You need to use mongorestore... which is used for things like importing json, or csv, etc.
You can read more about mongorestore in the docs below; I'd take a look and read up on them as they are very helpful.
http://www.mongodb.org/display/DOCS/Import+Export+Tools#ImportExportTools-mongorestore
You can also check out http://learnmongo.com for tips and help! or you can visit the links
How to use the dumped data by mongodump? hope this may be helpful for you.