There are advantages and disadvantages to using water or air as the respiratory medium from which an animal takes in oxygen. Which statement below is false? a. Aquatic animals do not have to worry about keeping their respiratory surfaces moist. b. Air has a higher concentration of oxygen than water and varies mostly with altitude only. c. Air has a constant concentration of 21 percent and water has a constant concentration of 6 percent. d. For terrestrial animals, air is easier to move over respiratory surfaces because it is less dense than water.

According to the Fick equation, the fish gill is an effective gas exchange surface because... A. It has a high blood-to-water diffusion distance B. The total surface area of the lamellae is very large C. The scaphognathite maintains a constant flow of water across the gill D. The gill tissue is supported by the surrounding water E. All of the above

88) During expiration, the diaphragm ________________________ Group of answer choices Contracts downward Relaxes downward Relaxes upward Contracts upward 89) The exchange of gases between the blood and systemic tissues is called ________________________ Group of answer choices Cellular Respiration Internal Respiration External Respiration Metabolism 90) There are 4 phases to hemostasis. Group of answer choices True False 91) Erythropoietin is released by the kidney as a result of detection high levels of oxygen in the blood.  Group of answer choices False True

The alveoli of mammalian lungs do not contain 20.9% O2 (that is, the percentage of O2 in atmospheric dry air) because    A. there is dead space in the trachea and bronchial tree and the air in the lungs is humidified.   B. mammals do not normally ventilate the lungs at a high enough rate.   C. the trachea and bronchi are too small in volume to contain this amount of O2.   D. mammal lungs have too many alveoli to ventilate.   E. some O2 has been exchanged with the blood before reaching the alveoli.