what is the main idea of the passage about microbes

HESI A2

Reading Comprehension HESI A2 Practice Test

1. What is the main idea of the passage about microbes?

A. Recent discoveries are revealing the critical role of microorganisms in maintaining a properly functioning immune system.
B. The human body is host to a staggering number of microorganisms.
C. Bacteriotherapy reintroduces healthy bacteria into a colon lacking the capability to defend against pathogenic agents.
D. Early research has shown remarkable discoveries in the possibilities of bacteriotherapy.

Correct answer: A

Rationale: The main idea of the passage is that recent discoveries are shedding light on the pivotal role of microorganisms in maintaining a properly functioning immune system. The passage discusses how the human body hosts a wide array of microorganisms, emphasizes the importance of these bacteria in the development of the immune system, and explores the potential applications of bacteriotherapy. Choice A is the correct answer because it accurately reflects the central theme discussed in the passage. Choices B, C, and D are incorrect because they focus on specific details or applications mentioned in the passage, rather than capturing the overarching theme of the critical role of microorganisms in immune system function.

2. What does Macmillan's invention of the bicycle signify?

A. He made important changes in bicycle design.
B. He invented the first bicycle with pedals.
C. He developed the modern chain drive.
D. He improved the safety of bicycles.

Correct answer: B

Rationale: Macmillan's invention of pedals was a significant milestone in bicycle history as it allowed for quicker and more efficient travel. The provided extract mentions that Macmillan's bicycle had foot-operated cranks like pedals, which enabled the rider to travel at a quick pace. This innovation marked a crucial development in the evolution of bicycles. While choices A, C, and D are related to advancements in bicycle design and safety, the key significance of Macmillan's invention lies in introducing pedals to bicycles, making choice B the correct answer.

3. Which of the following is not listed as a detail in the passage about A Short History of the CDC?

A. Where the organization began.
B. Who first ran the organization.
C. When the organization changed its name.
D. What divisions make up the current CDC.

Correct answer: D

Rationale: The passage does not provide specific details about the divisions that currently make up the CDC. Instead, it focuses on the organization's historical context, original goals, and overall mission. Thus, D is correct as it identifies information not covered in the passage.

4. What is the overall tone of the essay?

A. Apathetic
B. Fascinated
C. Discouraged
D. Hopeful

Correct answer: C

Rationale: The overall tone of the essay is discouraged, as it conveys concern over the United States’ lower ranking in life expectancy and highlights various health issues contributing to this situation. The language used suggests frustration and disappointment regarding the country's health statistics, supporting option C as the correct answer.

5. What is the meaning of the word 'evolved' in the first paragraph?

A. To spread
B. To gradually develop
C. To revolve
D. To shift

Correct answer: B

Rationale: In the context of the given extract, 'evolved' means to gradually develop. The systems in the body have evolved over time, indicating a gradual development and adaptation. 'To spread,' 'to revolve,' and 'to shift' do not capture the idea of a gradual development as portrayed in the text, making them incorrect choices.