(E) explain anaerobic glycolysis and its effects on animal survival
21. According to the author, glycogen is crucial to the process of anaerobic glycolysis because glycogen
(A) increases the organism's need for ATP
(B) reduces the amount of ATP in the tissues
(C) is an inhibitor of the oxidative metabolic production of ATP
(D) ensures that the synthesis of ATP will occur speedily
(E) is the material from which ATP is derived
22. According to the author, a major limitation of anaerobic glycolysis is that it can
(A) produce in large animals more lactic acid than the liver can safely reconvert
(B) necessitate a dangerously long recovery period in large animals
(C) produce energy more slowly than it can be used by large animals
(D) consume all of the available glycogen regardless of need
(E) reduce significantly the rate at which energy is produced by oxidative metabolism
23. The passage suggests that the total anaerobic energy reserves of a vertebrate are proportional to the vertebrate's size because
(A) larger vertebrates conserve more energy than smaller vertebrates
(B) larger vertebrates use less oxygen per unit weight than smaller vertebrates
(C) the ability of a vertebrate to consume food is a function of its size
(D) the amount of muscle tissue in a vertebrate is directly related to its size
(E) the size of a vertebrate is proportional to the quantity of energy it can utilize