#Question id: 4715
#Unit 11. Evolution and Behavior
Claytonia virginica is a woodland spring herb with flowers that vary from white, to pale pink, to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink to white flowers, so that Claytonia with pink flowers have greater relative fruit set than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. Given no other information, if the researcher removes all slugs from the study population, what do you expect to happen to the distribution of flower colors in the population over time?
#Question id: 177
#Unit 1. Molecules and their Interaction Relevant to Biology
The titration curve of alanine shows the ionization of two functional groups with pKa values of 2.34 and 9.69, corresponding to the ionization of the carboxyl and the protonated amino groups, respectively. The titration of di-, tri-, and larger oligopeptides of alanine also shows the ionization of only two functional groups, although the experimental pKa values are different. The trend in pKa values is summarized in the table. Which of the following is a reason for this shift in pK values
#Question id: 11007
#Unit 7. System Physiology – Animal
A 25-year-old, well-conditioned athlete weighs 80 kg (176 lb). During maximal sympathetic stimulation, what is the plateau level of his cardiac output function curve?
#Question id: 3799
#Unit 3. Fundamental Processes
If replicating bacteria are given a short pulse of radiolabeled thymidine and rapidly killed, the radiolabel shows up as:
#Question id: 11484
#Unit 7. System Physiology – Animal
Two students studying physiology taste a known "bitter" substance, and both report sensing bitterness. They then sample another substance. Student A reports sensing both a bitter taste and a salty taste, but student B reports only a salty taste. What is the most logical explanation?