The fact that astronomers have observed billions of stars clustered together is evidence that -- a. stars must have some sort of attraction for each other. b. all sections of space have the same numbers of stars. c. galaxies are probably older than the stars that make them up. d. the distance from one star to another varies, depending on the temperature of the star.

How are gene and protein sequences used to classify organisms?

Gregor mendel is best known for his work with pea plants and for uncover many of the mysteries of genetics. one of his major findings stated that there were specific, physical units of inheritance that are transmitted during reproduction. what is the the name given to these units of inheritance which can be found on chromosomes? a) centromeres b) cytoplasm c) genes d) nucleotides

What is the difference between a scientific hypotheses and a scientific theory?