A receptor that binds to a ligand at very low concentrations has a
A) High dissociation constant.
B) Low Ka.
C) High affinity for the ligand.
D) Low affinity for the ligand.
Answer: C
You might also like to view...
Durable intercellular connections that are abundant between cells in the superficial layers of the skin are called
A) tight junctions. B) gap junctions. C) desmosomes. D) CAMS. E) proteoglycans.
Select the description below that illustrates a difference between a sphincter and circular muscle
A) A sphincter is a thickening of circular muscle that can prevent the movement of digesting materials while circular muscle is involved in propulsion digesting material. B) Sphincters are found throughout the GI tract while circular muscle is found only in the proximal portion of the GI tract. C) A sphincter is composed of smooth muscle while circular muscle is composed of skeletal muscle tissue. D) Sphincters are found in the proximal portion of the GI tract while circular muscle is found in the distal portions.
Which is TRUE about the pleural sac?
A. It is continuous with the atmosphere and protects the lungs from infection. B. It is a closed sac surrounding each lung that contains only a tiny volume of lubricating fluid. C. It is a closed sac surrounding each lung and contains a large volume of surfactant. D. It is a closed, air-filled space surrounding both lungs that has a negative pressure compared to atmospheric pressure. E. It is bounded by pleural membranes that are very thin, which allows for abundant gas exchange.
Glands are formed from ________.
A. epithelial tissue B. connective tissue C. muscle tissue D. nerve tissue