SECTION 1: READING (45 Questions — 55 Minutes)
The Reading section assesses key ideas and details, craft and structure, and integration of
knowledge and ideas.
Passage 1 (Questions 1-5)
*The human circulatory system is a complex network of blood vessels, the heart, and blood
that transports oxygen, nutrients, hormones, and waste products throughout the body. The
heart, a muscular organ approximately the size of a fist, functions as a pump that propels
blood through two distinct circuits: the pulmonary circuit and the systemic circuit. The
pulmonary circuit carries deoxygenated blood from the right side of the heart to the lungs,
where carbon dioxide is exchanged for oxygen. The systemic circuit carries oxygenated
blood from the left side of the heart to the rest of the body, delivering oxygen and nutrients
to tissues and removing waste products. The circulatory system is essential for maintaining
homeostasis, as it helps regulate body temperature, pH balance, and fluid balance.*
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**1.** What is the primary function of the pulmonary circuit?
A) To deliver oxygenated blood to the body's tissues
B) To exchange carbon dioxide for oxygen in the lungs
C) To pump blood through the systemic circulation
D) To transport nutrients from the digestive system
**Correct Answer:** B) To exchange carbon dioxide for oxygen in the lungs
,**Rationale:** The passage explicitly states that the pulmonary circuit "carries
deoxygenated blood from the right side of the heart to the lungs, where carbon dioxide is
exchanged for oxygen." Option A describes the systemic circuit; Option C describes the
heart's overall function; Option D refers to nutrient transport.
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**2.** According to the passage, what is the role of the heart in the circulatory system?
A) To filter waste products from the blood
B) To produce red blood cells
C) To pump blood through the pulmonary and systemic circuits
D) To regulate body temperature
**Correct Answer:** C) To pump blood through the pulmonary and systemic circuits
**Rationale:** The passage states that the heart "functions as a pump that propels blood
through two distinct circuits: the pulmonary circuit and the systemic circuit." Option A
describes the kidneys; Option B describes the bone marrow.
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**3.** What is the systemic circuit responsible for?
A) Exchanging carbon dioxide for oxygen in the lungs
B) Delivering oxygenated blood to the body's tissues
C) Pumping blood from the right side of the heart
D) Regulating blood pH
, **Correct Answer:** B) Delivering oxygenated blood to the body's tissues
**Rationale:** The passage states that the systemic circuit "carries oxygenated blood from
the left side of the heart to the rest of the body, delivering oxygen and nutrients to tissues
and removing waste products."
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**4.** Which of the following is the best summary of the passage?
A) The heart is a muscular organ that pumps blood through the body.
B) The circulatory system transports blood through the pulmonary and systemic circuits
and is essential for maintaining homeostasis.
C) The lungs exchange carbon dioxide for oxygen in the blood.
D) The circulatory system is not important for maintaining homeostasis.
**Correct Answer:** B) The circulatory system transports blood through the pulmonary and
systemic circuits and is essential for maintaining homeostasis.
**Rationale:** The passage covers the structure of the circulatory system (heart, blood
vessels, blood), the two circuits, and its role in maintaining homeostasis. Option B
captures the full scope of the passage.
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**5.** Which of the following is NOT mentioned as a function of the circulatory system?