20. Occasionally cells stop dividing and enter another phase, G. If you damage your liver, new liver cells can be produced to replace up to 75% of the liver. However, if you sustain brain dam-
age, your body does not produce new brain cells. Explain this observation using what you have
learned about the cell cycle.

M! (1). what are the inputs and the outputs for cellular respiration? (2). what is the primary source of energy for cellular respiration?

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 is used as a template during replication? a- mrna b- trna c- rrna d- dna