An independent variable is that which is:
a. changed by the scientist.
b. observed to develop a hypothesis.
c. kept constant.
d. measured by the scientist.

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.

Alaska and northern canada have a diet rich in vitamin d and their skin color is darker than predicted on the basis of iv intensity at their latitude. explain the observation:

Which of the following is a cause of a dna mutation? o a. the linking of amino acid subunits into a long chain o b. the transcription of dna into rna o c. an error in the repair of damaged dna d. the diffusion of molecules across the cell membrane submit