Without Morph Ball Bombs: Transport Tunnel A

Notes:

Use a Boost Jump to get through Transport Tunnel A going either way without using Morph Ball Bombs. This is necessary in some randomized games.
Going left, the Morph Ball will not climb the rock on its own, regardless of which direction you hold on the Analog Stick (this phenomenon is described in more detail on the Boost Jump page). Also, apparently because of the breakable block, Boosting from the right does not seem to yield the correct upward bounce against the rock face most of the time. Instead, try simply rolling into the rock, as shown in the video. You will need to release your Boost only a few frames after the ball collides with the wall and begins to travel upward. This is much more difficult than it looks.
Going right is much easier, because the ball will climb on its own. Simply tilt the Analog Stick slightly down or slightly up (in addition to holding right), and the ball will begin to jump up the breakable block on its own, as shown in the video. Then you just need to release your Boost a few frames after a climb begins.