Explain the difference between a star going through interste…

Explain the difference between a star going through interstellar reddening and a star that is redshifted. To do this, comment on the following: a.) What is causing the reddening and redshift? b.) How would the absorption spectrum for the stars differ? Comment both on the position of the spectral lines and their strength (how bright each line appears to be).

After graduation, you and 19 friends build a raft, sail to a…

After graduation, you and 19 friends build a raft, sail to a deserted island, and start a new population, totally isolated from the world. Two of your friends carry (that is, are heterozygous for) the recessive cf allele, which in homozygotes causes cystic fibrosis. Assuming that the frequency of this allele does not change as the population grows, what will be the instance of cystic fibrosis on your island?