Question

a science class is learning about the types of galaxies. students are broken into four groups, and each group is creating a project and presentation about one galaxy. one group is assigned the irregular galaxy. which statement best describes the irregular galaxy? a irregular galaxies have two main shapes: oval and pinwheel. irregular galaxies are the biggest galaxies, and they each have a bulge in the center. b irregular galaxies have no specific shape and are made up of gas and dust. these galaxies have both young and old stars. c irregular galaxies have an elliptical shape and can sometimes have a bulge in the center. they are made up of mostly gas, dust, and old stars. d irregular galaxies are held together by gravity and have a circular shape with a halo. they are made up of stars but have very little gas and dust.

Explanation:

To determine the correct statement about irregular galaxies, we analyze each option:

• Option A: Irregular galaxies do not have oval or pinwheel (spiral) shapes, and the "biggest galaxies" description is incorrect (ellipticals are often larger). Also, the "bulge in the center" is not a feature of irregulars. Eliminate A.
• Option B: Irregular galaxies have no specific shape, are composed of gas, dust, and contain both young and old stars. This matches the characteristics of irregular galaxies.
• Option C: An elliptical shape is a feature of elliptical galaxies, not irregulars. Eliminate C.
• Option D: A circular shape with a halo and "mostly old stars with little gas and dust" describes elliptical or spiral galaxies (with halos), not irregulars. Irregulars have more gas/dust for star formation. Eliminate D.

Answer:

B. IRREGULAR GALAXIES HAVE NO SPECIFIC SHAPE AND ARE MADE UP OF GAS AND DUST. THESE GALAXIES HAVE BOTH YOUNG AND OLD STARS.