Are marketing and business development playing the same game, on the same team, and using the same game plan for maximizing sales & profit?

NO SIR,,, THEY HAVE DIFFERENT JOBS TO DO............. 

Business development is a separate function and starts their job even before a company commences its production/commercial operation and aims at far reaching goals.  Marketing is more or less an activity for the present and if the scope expands it may be tend to business development activities.  

Good Day!!!

To my opinion, When a marketing plan is finalized and ready to implement, the role of business development starts.

Both the terms used interchangeably in certain organizations but have different roles as well some overlapping jobs as well.

Yes they're also the same team, because they're related from each other to another

No they both are very different streams