Zipping The Contents Of Directory

Zip the contents of a directory (/path/to/dir/*) and then include a file in that zip that is located here: /a/whole/different/path/file.jpg. Is there a ZIP parameter that allows me to include that JPG file in the ZIP file that I am creating? Can someone give me the command?

Also, instead of zipping the contents inside of the "dir" directory, can I zip the "dir" directory itself but exclude the full path when creating the zip (/path/to/ part). I can do this with the -j parameter but when I do it also excludes the "dir" directory and only ZIPs the content inside of it.