The human body's arterial blood pH is tightly maintained around 7.4 by buffering agents that bind hydrogen ions to stop any change in pH. If an acid-base imbalance overcomes the buffer system, the body changes the ventilation rate, or the rate at which gas enters or leaves the lungs. Changing the ventilation rate changes the concentration of CO2 in the blood, which alters the pH of the blood. In this case, pH 7.4 is the:
A. set point.
B. sensor.
C. integrator.
D. effector.
E. homeostatic challenge.
Answer: A
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Hammer-head bats are a species of African fruit bats. During the breeding season, males gather in mating arenas, where they display to females who pass through and assess males before selecting individuals with which to mate
This is an example of ____ (intra/inter) sexual selection. Fill in the blank with the appropriate word.
The breast muscle of turkeys and chickens is usually referred to as light meat, whereas that of wild ducks and geese is described as dark meat. Which of the following is consistent with this observation?
A. Turkeys and chickens are not closely related to ducks and geese. B. Turkeys and chickens do not use their breast muscle, ducks and geese do. C. Turkeys and chickens do not fly for sustained periods, whereas wild ducks and geese do. D. The muscles of ducks and geese do not contain myosins. E. The darker body color of ducks and geese provides protective camouflage against predators.
Some members of the Archaea domain are often referred to as extremophiles because many live in conditions of extreme
A. temperature. B. salinity. C. heat. D. acidity. E. All of the answer choices are correct.
Which theory of water transport states that
hydrogen bonding allows water molecules to maintain a continuous fluid column as water is pulled from roots to leaves?
a. pressure flow b. evaporation c. cohesion-tension d. abscission e. fusion