Use these questions to test your understanding. If you get them wrong, you will be linked back to the relevant part of the notes. 

Be sure you study them thoroughly (don't just get a quick fix for your mistake) so your overall understanding is improved.

1. Spiral arms are prominent in some galaxies because

   a. they mark where the dust is thin and we can see the stars better

   b. they show where young and bright stars have formed

   c. they represent bright blobs that have been wound into the spiral shape by the galaxy rotation

   d. Population III stars make them bright

   e. they mark where material has been ejected by the nucleus

2. The various types of galaxy

   a. show a sequence that evolves with age from one to the other

   b. include spirals, ellipticals, and irregulars

   c. are a result of different distances to them and the resulting limits to the amount of detail we can see

   d. are only apparent in the visible spectral range

   e. show they are made of different types of matter

3. The Milky Way is a

   a. barred spiral galaxy

   b. elliptical galaxy

   c. irregular galaxy

   d. Sa galaxy

   e. we do not have much idea of what type it is

4. What do we call the bright, roughly spherical, collection of old stars around the center of the Milky Way?

   a. disk

   b. halo

   c. bulge

   d. spiral arms

   e. dark matter

5. Stars with high concentrations of elements heavier than hydrogen and helium

   a. are likely to be very old

   b. are found in globular clusters

   c. are likely to have formed relatively recently

   d. are members of population II

   e. have very low mass

6. We see where the young stars are in a galaxy most easily when we look in

   a. the visible and near infrared

   b. the ultraviolet and far infrared

   c. the X-ray and ultraviolet

   d. the radio and gamma ray

   e. the visible and X-ray

7. Galaxies at very high redshift are

   a. just like those near us

   b. seem to be smaller and younger than typical ones near us

   c. are mostly elliptical galaxies

   d. are prominent because of their radio emission

   e. all have active nuclei