All correct in 11 mins 40 seconds, including 4 mins 30 seconds to read
Para 1- rate of oxidative metabolism, high metabolic rate of small animals vs low metabolic rate of very large animals, anaerobic glycolysis, the great equalizer
Para 2- anaerobic glycolysis- the quick firepower, how many large species have managed to compete with their more active neighbors
Para 3- limitations- glycogen reserves for upto 2 mins, lactic acid; muscle glycogen is used only when needed and even then only in whatever quantity is necessary
1. The primary purpose of the passage is to (E) explain anaerobic glycolysis and its effects on animal survival - Correct, the process is explained in para 2 and its effects on animal survival is also stated
2. According to the author, glycogen is crucial to the process of anaerobic glycolysis because glycogen (E) is the material from which ATP is derived
Anaerobic glycolysis is a process in which energy is produced, without oxygen, through the breakdown of muscle glycogen into lactic acid and adenosine triphosphate (ATP), the energy provider.
3. According to the author, a major limitation of anaerobic glycolysis is that it can (B) necessitate a dangerously long recovery period in large animals
It might seem that this interminably long recovery time in a large vertebrate would prove a grave disadvantage for survival.
4. The passage suggests that the total anaerobic energy reserves of a vertebrate are proportional to the vertebrate's size because (D) the amount of muscle tissue in a vertebrate is directly related to its size
The amount of energy that can be produced anaerobically is a function of the amount of glycogen present-in all vertebrates about 0.5 percent of their muscles' wet weight. Thus the anaerobic energy reserves of a vertebrate are proportional to the size of the animal.
5. The author suggests that, on the basis of energy production, a 100-ton dinosaur would have been markedly vulnerable to which of the following? I. Repeated attacks by a single smaller, more active adversary - incorrect, a single smaller more active adversary won't be of much issue
II. Sustained attack by numerous smaller, more active adversaries - Correct, If only oxidative metabolic rate is considered, therefore, one might assume that smaller, more active, animals could prey on larger ones, at least if they attacked in groups.
III. An attack by an individual adversary of similar size - incorrect
6. It can be inferred from the passage that the time required to replenish muscle glycogen following anaerobic glycolysis is determined by- which of the following factors? With the conclusion of a burst of activity, the lactic acid level is high in the body fluids, leaving the large animal vulnerable to attack until the acid is reconverted, via oxidative metabolism, by the liver into glucose, which is then sent (in part) back to the muscles for glycogen resynthesis.
Fortunately, muscle glycogen is used only when needed and even then only in whatever quantity is necessary.
I. Rate of oxidative metabolism
II. Quantity of lactic acid in the body fluids
III. Percentage of glucose that is returned to the muscles
(E) I, II, and III
I took a lot of time in choosing/rejecting option III since the percentage of glucose isn't explicit.
7. The author is most probably addressing which of the following audiences? (A) College students in an introductory course on animal physiology - Correct
(B) Historians of science investigating the discovery of anaerobic glycolysis - incorrect
(C) Graduate students with specialized training in comparative anatomy - incorrect, there is no specific discussion about anatomy( I eliminated this option at the end)
(D) Zoologists interested in prehistoric animals - irrelevant, dinosaurs are just one example of very large animals
(E) Biochemists doing research on oxidative metabolism - incorrect, the passage has elementary information and is unlikely to be of importance to biochemists doing R&D
8. Which of the following best states the central idea of the passage? (A) The disadvantage of a low oxidative metabolic rate in large animals can. be offset by their ability to convert substantial amounts of glycogen into energy. - Correct
(D) The major factor ensuring that a large animal will triumph over a smaller animal is the large animal's ability to produce energy via anaerobic glycolysis. - incorrect
I was down to option A and D and felt option A is better because I wasn't whether calling anaerobic glycolysis a major factor is correct and option A seemed better