The functional unit of a skeletal muscle cell (i.e., where the contraction/shortening actually occurs) is the:

Regarding hemoglobin, which of the following would unload oxygen most readily?

ESSAY: Secondary antibody response When you get vaccinated against a disease such as covid-19, the vaccination prompts your immune system to mount a primary antibody response, and also creates memory B cells for a secondary response in case you are re-exposed to the same antigen again in the future. a. Describe the characteristics of the secondary antibody response by memory B cells (hint: consider and compare the graphs we studied illustrating the primary vs secondary response characteristics).  Be specific and detailed. b. Discuss why this secondary response prevents you from becoming ill (or at least not severely ill) when, someday in the future, you are re-exposed to the same germ that you were vaccinated against.

Which of the following statements about the body’s defenses is FALSE?

Which of the following is the normal sequence of electrical signal conduction in the heart?

Which of the following processes is TRUE for the loop of Henle?

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?