The occurrence of the same blood protein in a group of species provides evidence that these species:

a. descended from different ancestors.

b. evolved in different habitats.

c. evolved in the same habitat.

d. descended from a common ancestor.

a

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation:

the rocks are classified by the geological process they are formed by. the three main groups of rocks are igneous, metamorphic, and sedimentary. minerals are not they are classified under the chemical classes they are in. these groups include silicates, sulfates and carbonates.