1. Are you curious as to whether you can build significant muscle by only training with bodyweight movements? 
2. Are exercises such as push-ups and pull-ups enough to transform your muscle mass? 
3. How far can bodyweight exercises take you in terms of your muscle gains? 

Push-ups and pull-ups are powerful bodyweight exercises. When it comes down to it you can definitely create a strong lean physique from doing push-ups and pull-ups several days a week. There is a very good reason these two movements are the staples for nearly every military, fight gym, and private box gym all over the globe!