A student is comparing physical versus chemical changes using sugar cubes. Which part of the student's experiment illustrates a chemical change?

A
Melting a sugar cube using a hotplate

B
Burning a sugar cube in a flame

C
Dissolving a sugar cube in water

D
Crushing a sugar cube with a mortar and pestle

How is ribosomal rna useful as a molecular clock? a. a large portion of the dna ring is not vital to structure or function, allowing it to accumulate neutral mutations. b. its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. c. a slow mutation rate makes it useful for determining evolutionary relationships between ancient species. d. it is only found in select organisms, making it easier to compare relationships between species that have it.

What property of water provides for appropriate sugar, salt, and amino acid levels to be present and carried in the blood of animals to be delivered to cells

Which of the following would involve looking at different structures of organisms and comparing how similar they are? a. vestigial structuresb. radiometric datingc. homologous structures