what is the meaning of the word shifts as used in the third paragraph

HESI A2

HESI A2 Reading Comprehension

1. What is the meaning of the word 'shifts' as used in the third paragraph?

A. Alterations
B. Stints
C. Removals
D. Transfers

Correct answer: A

Rationale: In this context, 'shifts' refers to changes or alterations in brain chemistry and electrophysiology. The word 'alterations' best captures the idea that significant changes are occurring in the brain. 'Stints' (choice B) refer to short periods of time or work, which is not the meaning intended here. 'Removals' (choice C) and 'transfers' (choice D) do not fit the context of the sentence and are not related to the changes happening in the brain as described in the extract.

2. A reader might infer from this passage that ___________.

A. Obesity can be detrimental to a long life
B. Car crashes are most frequent in the United States
C. The Second Amendment should be overturned
D. People in Asia and Africa have the shortest life spans

Correct answer: A

Rationale: The passage indicates that obesity, along with other health-related issues, contributes to lower life expectancy. This implies that obesity can negatively affect one's lifespan, making option A the correct inference based on the information presented in the text. The other options do not accurately reflect the implications of the passage.

3. What conclusion can be drawn from the passage on the Amazon Rainforest?

A. The Amazon Rainforest is shrinking at a rapid pace.
B. The Amazon Rainforest is not affected by human activity.
C. The Amazon Rainforest will survive indefinitely.
D. The Amazon Rainforest has no significant impact on global warming.

Correct answer: A

Rationale: The correct conclusion that can be drawn from the passage on the Amazon Rainforest is that it is shrinking at a rapid pace. The passage explicitly mentions the rapid deforestation and shrinking of the Amazon Rainforest due to human activities like logging and burning. This conclusion is supported by the alarming statistics provided, such as 9,169 square miles of forest being cut down in Brazil in 2003, and an area of rainforest the size of a football field being burned down every minute. This rapid destruction poses a significant threat to the survival of the Amazon Rainforest and its biodiversity. Choice B is incorrect as the passage clearly states that human activities are causing harm to the rainforest. Choice C is incorrect because the passage highlights the current dangers and threats faced by the Amazon Rainforest, indicating that its survival is at risk. Choice D is also incorrect as the passage clearly explains the significant impact of deforestation in the Amazon Rainforest on global warming due to the release of carbon dioxide into the atmosphere.

4. What are the three steps of the 'wave of excitation'?

A. The discharge from the SA node, the peak ECG, and the excitement of the ventricle.
B. The excitement of the ventricle, the relaxing of the ventricle, and the systemic neural response.
C. The contraction of the atrium, the relaxation of the atrium, and the contraction of the ventricle.
D. The excitation of the atrium, the excitement of the ventricle, and the relaxing of the ventricle.

Correct answer: D

Rationale: The correct steps of the 'wave of excitation' are the excitation of the atrium, excitement of the ventricle, and relaxation of the ventricle. In the described process, the 'wave of excitation' starts with the discharge from the SA node, leading to the excitation of the atrium. Next, the peak ECG corresponds to the excitement of the ventricle, not its relaxation. Finally, the wave concludes with the relaxation of the ventricle, not its contraction. Therefore, choices A, B, and C are incorrect as they do not accurately describe the sequential steps of the 'wave of excitation' as presented in the extract.

5. What is the meaning of the word duration as used in the last paragraph?

A. Basis
B. Extent
C. Cure
D. Solidity

Correct answer: B

Rationale: The word "duration" in the context of sleep refers to the length of time that children should sleep. It suggests a focus on the amount of sleep necessary for healthy development, making option B the correct choice as it aligns with the emphasis on recommended sleep hours for children.