Galaxy Formation Quiz

The two factors that are most likely to affect whether a galaxy will evolve by merging with a second galaxy are:

1. **its size compared to that of the other galaxy** - The size and mass of galaxies play a crucial role in their gravitational interactions and the likelihood of merging.

2. **its distance from the other galaxy** - The proximity of galaxies to one another greatly influences their ability to merge; galaxies that are closer together are more likely to interact gravitationally and potentially merge over time.

So the correct answers are:
- its size compared to that of the other galaxy
- its distance from the other galaxy