What do genetic engineers do to obtain bacteria that produce insulin

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

What’s a example of extrusive rock that cooled to quickly for grains to form

Which statement does lola need to correct, and why? a) statement 1 because spiral galaxies do not havearmsb) statement 2 because the bulges contain mostlyyoung red stars. c) statement 3 because the arms are made of mostlyyoung blue and blue-white stars. d) statement 4 because spirals galaxies contain littleto no dust.(c)