Entry Exam Category: College Admission Exams
Course: Accuplacer
Exam: Accuplacer Reading Comprehension Practice Test
Practice Question
Extract
The reduction in environmental awareness that defines sleep renders animals vulnerable to predation. Although animals can dilute this risk by sleeping in groups, the benefit is greatest for those in the center, farthest from approaching predators. Indeed, mallards (Anas platyrhynchos) switch from sleeping with both eyes closed and both cerebral hemispheres [bihemispheric slow-wave sleep (BSWS)] when safely flanked by other birds to sleeping unihemispherically, with one eye open and the contralateral hemisphere awake, when exposed at the edge of a group. As sleeping at the edge is risky and results in lower quality unihemispheric slow-wave sleep (USWS), birds likely compete to obtain and defend a central position within the group, especially when nesting in colonies. However, in colonial birds, such as penguins, intraspecific aggression from neighbors and disturbance from birds walking through the colony might have a negative impact on sleep. Given the threat from outside and the hustle and bustle within the colony, it is unclear whether nesting in the center of a colony leads to better sleep quantity and quality.
Which choice best describes the overall structure of the passage?
Answer Choices
- A: The passage examines the effect of decreased environmental awareness on some animals' predation risk and then describes the strategies those animals use to increase their environmental awareness while sleeping.
- B: The passage distinguishes between bihemispheric slow-wave sleep (BSWS) and unihemispheric slow-wave sleep (USWS) and then explains why USWS is less beneficial than BSWS for animals such as mallards and penguins.
- C: The passage discusses the advantages for some animals of sleeping at the center of a group and then questions whether those advantages extend to colonial birds.
- D: The passage provides an extended description of how mallards typically sleep and then compares sleeping behaviors in mallards to those in penguins.
Correct Answer: C
Rationale: The passage first explains that animals benefit from sleeping in the center of a group due to reduced predation risk and better sleep quality. It then shifts to questioning whether this benefit applies to colonial birds like penguins, who face different challenges (e.g., intraspecific aggression, disturbances). Thus, option C best captures the passage’s structure.