Aperson can eat when hunger is absent because: a. the hypothalamus signals availability of food in the environment. b. the hypothalamus monitors the availability of nutrients. c. the stomach intensifies its contractions and creates hunger pangs. d. the conscious mind of the cortex can override body signals. e. the digestive tract sends messages to the hypothalamus.

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.