A lion and a tiger mate in a zoo; their offspring survive to adulthood but cannot create viable sperm or eggs. This result demonstrates that, as species, lions and tigers are reproductively isolated due to which of the following mechanisms?

A recording of the electrical activity of a patient’s heart shows that the atria are contracting regularly and normally, but every few beats the ventricles fail to contract. Which of the following probably is not functioning properly?

Which of the following is NOT required for transmission of an action potential’s signal across a chemical synapse?

A new 8 lane highway is built through the center of a snail’s geographic range. Since this highway is too wide and dry for a snail to survive when trying to cross the road, snails on the east side of the highway can no longer breed with snails on the west side of the highway. Decades later, biologists reclassify the ancestral lineage into two new species. Which mode of speciation has occurred?

Which of the following conditions is NOT required for the Hardy-Weinberg equilibrium?

When an action potential from a motor neuron arrives at the neuromuscular junction, a series of events occurs that leads to the contraction of the skeletal muscle cell. Which of the following events occurs last?  (Hint: put these events in the correct order first, so you can easily decide which event occurs last.)

If the observed f(RR)=0.3, f(Rr)=0.2, and f(rr)=0.5, what is f(r)? (Note: a calculator is available in Canvas, or on the the classroom’s counter, if you’d like to use one.)

During an action potential, the local axon membrane repolarizes from +40 mV to -75 mV because of:

FILL-IN: In the eggs of Class Reptilia and Class Mammalia, what is the function of the amnion (an extra-embryonic membrane within the amniotic egg)? Answer in a few words.  

Which of the following statements about skeletal muscle cells and cardiac muscle cells is FALSE?