How are rocks that cooled within magma chambers found on earth’s surface today? they are pushed up by magma under earth’s surface. they are revealed by erosion of earth’s surface over time. they are pushed to earth’s surface because of their larger size. they are revealed at earth’s surface due to their low density.

The correct answer is - They are revealed by erosion of Earth's surface over time.

The rocks that have formed by cooling within the magma chambers, thus deeper inside of the volcano, managed to come on the surface because of the erosion that has lowered the layers above them.

The weathering and erosion are processes that have the tendency to lower and flatten the landscape by breaking apart the rocks on the surface. Over longer periods of time, they are able to remove lot of layers from the surface, thus exposing what has been buried deep inside the ground long time ago. That is how the rocks formed in the magma chambers manage to reach the surface.

answer; polycythemia is the correct answer;

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."