What role does gravity play in a galaxy?

Gravity plays a crucial role in the structure and behavior of a galaxy. It acts as the fundamental force that binds the galaxy together, influencing the overall mass distribution and the dynamics of its components, such as stars, gas, dust, and dark matter. The gravitational attraction among these elements ensures that they remain in a cohesive structure, preventing them from dispersing into space.

Moreover, gravity influences the movement of stars within the galaxy. As stars orbit the galactic center, their paths are dictated by the gravitational forces exerted by the massive core of the galaxy and the surrounding matter. This interaction not only shapes the orbits of stars but also plays a pivotal role in the processes of star formation and evolution over time.

In contrast, the other options are too limited in scope, as they do not account for the comprehensive role gravity plays within the entirety of a galaxy’s structure and dynamics. Gravity is much more than just a factor influencing star formation or planet motion; it is the very force that maintains the integrity of the galaxy as a whole.