Final answer:
The Pinwheel Galaxy (M101) is a large face-on spiral galaxy with active star formation in its bluer arms, and a yellowish bulge indicating older star populations.
Step-by-step explanation:
M101, also known as the Pinwheel Galaxy, exhibits a classic face-on spiral shape. It is situated about 21 million light-years away from Earth and is nearly double the diameter of the Milky Way, consisting of approximately 1 trillion stars. Its colorful arms are indicative of active star formation, which can be identified by their bluer hues compared to the galaxy's bulge.
The bulge of the galaxy typically appears yellower because it is composed primarily of older, cooler stars. The color contrast between the spiral arms and the bulge suggests the presence of different types of star populations within the galaxy.