BIO 201 Anatomy & Physiology I – Complete 500-
Question Practice Exam 2026
Overview
This comprehensive 500-question practice exam is designed for students preparing for the BIO
201 Anatomy & Physiology I course at StraighterLine. It covers all major topics including
anatomical terminology, chemistry for A&P, cells and tissues, integumentary system, skeletal
system, joints, muscular system, nervous system, special senses, and the endocrine system.
Each question includes the correct answer and a detailed rationale to reinforce understanding.
The material is based on standard StraighterLine BIO201 curricula, OpenStax Anatomy and
Physiology , and ACE-recommended learning outcomes . Use this as a primary study resource
for module exams, the midterm, and the cumulative final exam.
EXAM 1: INTRODUCTION, CHEMISTRY, AND HOMEOSTASIS
Questions 1–100
1. Which of the following represents the correct order of structural organization from simplest
to most complex?
A) Tissue → Organ → Cell → Organ system → Organism
B) Cell → Tissue → Organ → Organ system → Organism
C) Organ → Tissue → Cell → Organism → Organ system
D) Cell → Organ → Tissue → Organ system → Organism
Correct Answer: B
Rationale: The structural organization of the body begins at the chemical level and proceeds to
cellular, tissue, organ, organ system, and organism levels. Cells are the basic unit of life; tissues
are groups of cells with similar function; organs are structures composed of multiple tissues;
organ systems work together to maintain homeostasis .
2. The study of tissues is called:
A) Cytology
B) Histology
C) Molecular biology
D) Microbiology
E) Surface anatomy
,Correct Answer: B
Rationale: Histology is the study of tissues. Cytology is the study of cells, molecular biology
studies biological molecules, microbiology studies microorganisms, and surface anatomy
studies external body structures .
3. An anatomic image created from sound waves is a:
A) Radiograph
B) CT scan
C) MRI
D) Sonogram
Correct Answer: D
Rationale: Sonography (ultrasound) uses high-frequency sound waves to create images of
internal body structures. Radiographs use X-rays, CT scans use multiple X-ray images, and MRI
uses magnetic fields .
4. What does the term "proximal" refer to in directional anatomy?
A) Pointing toward the side of the body
B) A position nearer to the trunk of the body
C) A position away from the surface of the body
D) A position lower than another part of the body
Correct Answer: B
Rationale: Proximal means closer to the point of attachment to the trunk or the trunk itself.
Distal means farther from the trunk. Lateral means toward the side, and deep means away
from the surface .
5. Which body cavity contains the pleural cavity?
A) Abdominopelvic cavity
B) Dorsal cavity
C) Thoracic cavity
D) Cranial cavity
Correct Answer: C
,Rationale: The pleural cavity surrounds the lungs and is located within the thoracic cavity. The
thoracic cavity also contains the pericardial cavity (heart) and the mediastinum .
6. A cut that divides the body into anterior and posterior portions is called a:
A) Transverse plane
B) Sagittal plane
C) Coronal (frontal) plane
D) Oblique plane
Correct Answer: C
Rationale: The coronal (frontal) plane divides the body into anterior (front) and posterior (back)
sections. A transverse plane divides into superior and inferior; sagittal divides into left and
right .
7. The visceral pleura is:
A) A double-layered serous membrane that anchors some abdominal organs
B) The serous membrane that covers the lungs
C) The serous membrane that lines the abdominal and pelvic cavities
D) The space located between the visceral and parietal pleura
Correct Answer: B
Rationale: The visceral pleura is the serous membrane that directly covers the lungs. The
parietal pleura lines the thoracic cavity wall. The pleural cavity is the space between them .
8. Imagine the following scenario: Platelets adhere to a damaged blood vessel → Platelets
secrete various substances → Platelets adhere to a damaged blood vessel. This is an example of
_____ feedback.
A) Positive
B) Negative
Correct Answer: A
Rationale: This describes a positive feedback mechanism because the response amplifies the
initial stimulus. Platelet adhesion triggers more platelet adhesion, accelerating blood clotting
until the vessel is sealed .
, 9. In a negative feedback loop, the effector's response:
A) Amplifies the initial stimulus
B) Reverses the initial stimulus
C) Ignores the stimulus
D) Creates a new stimulus
Correct Answer: B
Rationale: Negative feedback mechanisms work to reverse or reduce the initial stimulus to
maintain homeostasis. For example, when body temperature rises, mechanisms are activated
to cool the body .
10. Which subatomic particle carries a positive charge and is found in the nucleus?
A) Electron
B) Neutron
C) Proton
D) Ion
Correct Answer: C
Rationale: Protons carry a positive charge and are located in the nucleus. Neutrons are neutral,
electrons are negatively charged and orbit the nucleus .
11. Isotopes of the same element differ in their number of:
A) Protons
B) Electrons
C) Neutrons
D) Ions
Correct Answer: C
Rationale: Isotopes are atoms of the same element that have the same number of protons but
different numbers of neutrons. This difference in neutron number affects atomic mass .
12. The valence shell of an atom refers to:
A) The innermost electron shell
B) The outermost electron shell
Question Practice Exam 2026
Overview
This comprehensive 500-question practice exam is designed for students preparing for the BIO
201 Anatomy & Physiology I course at StraighterLine. It covers all major topics including
anatomical terminology, chemistry for A&P, cells and tissues, integumentary system, skeletal
system, joints, muscular system, nervous system, special senses, and the endocrine system.
Each question includes the correct answer and a detailed rationale to reinforce understanding.
The material is based on standard StraighterLine BIO201 curricula, OpenStax Anatomy and
Physiology , and ACE-recommended learning outcomes . Use this as a primary study resource
for module exams, the midterm, and the cumulative final exam.
EXAM 1: INTRODUCTION, CHEMISTRY, AND HOMEOSTASIS
Questions 1–100
1. Which of the following represents the correct order of structural organization from simplest
to most complex?
A) Tissue → Organ → Cell → Organ system → Organism
B) Cell → Tissue → Organ → Organ system → Organism
C) Organ → Tissue → Cell → Organism → Organ system
D) Cell → Organ → Tissue → Organ system → Organism
Correct Answer: B
Rationale: The structural organization of the body begins at the chemical level and proceeds to
cellular, tissue, organ, organ system, and organism levels. Cells are the basic unit of life; tissues
are groups of cells with similar function; organs are structures composed of multiple tissues;
organ systems work together to maintain homeostasis .
2. The study of tissues is called:
A) Cytology
B) Histology
C) Molecular biology
D) Microbiology
E) Surface anatomy
,Correct Answer: B
Rationale: Histology is the study of tissues. Cytology is the study of cells, molecular biology
studies biological molecules, microbiology studies microorganisms, and surface anatomy
studies external body structures .
3. An anatomic image created from sound waves is a:
A) Radiograph
B) CT scan
C) MRI
D) Sonogram
Correct Answer: D
Rationale: Sonography (ultrasound) uses high-frequency sound waves to create images of
internal body structures. Radiographs use X-rays, CT scans use multiple X-ray images, and MRI
uses magnetic fields .
4. What does the term "proximal" refer to in directional anatomy?
A) Pointing toward the side of the body
B) A position nearer to the trunk of the body
C) A position away from the surface of the body
D) A position lower than another part of the body
Correct Answer: B
Rationale: Proximal means closer to the point of attachment to the trunk or the trunk itself.
Distal means farther from the trunk. Lateral means toward the side, and deep means away
from the surface .
5. Which body cavity contains the pleural cavity?
A) Abdominopelvic cavity
B) Dorsal cavity
C) Thoracic cavity
D) Cranial cavity
Correct Answer: C
,Rationale: The pleural cavity surrounds the lungs and is located within the thoracic cavity. The
thoracic cavity also contains the pericardial cavity (heart) and the mediastinum .
6. A cut that divides the body into anterior and posterior portions is called a:
A) Transverse plane
B) Sagittal plane
C) Coronal (frontal) plane
D) Oblique plane
Correct Answer: C
Rationale: The coronal (frontal) plane divides the body into anterior (front) and posterior (back)
sections. A transverse plane divides into superior and inferior; sagittal divides into left and
right .
7. The visceral pleura is:
A) A double-layered serous membrane that anchors some abdominal organs
B) The serous membrane that covers the lungs
C) The serous membrane that lines the abdominal and pelvic cavities
D) The space located between the visceral and parietal pleura
Correct Answer: B
Rationale: The visceral pleura is the serous membrane that directly covers the lungs. The
parietal pleura lines the thoracic cavity wall. The pleural cavity is the space between them .
8. Imagine the following scenario: Platelets adhere to a damaged blood vessel → Platelets
secrete various substances → Platelets adhere to a damaged blood vessel. This is an example of
_____ feedback.
A) Positive
B) Negative
Correct Answer: A
Rationale: This describes a positive feedback mechanism because the response amplifies the
initial stimulus. Platelet adhesion triggers more platelet adhesion, accelerating blood clotting
until the vessel is sealed .
, 9. In a negative feedback loop, the effector's response:
A) Amplifies the initial stimulus
B) Reverses the initial stimulus
C) Ignores the stimulus
D) Creates a new stimulus
Correct Answer: B
Rationale: Negative feedback mechanisms work to reverse or reduce the initial stimulus to
maintain homeostasis. For example, when body temperature rises, mechanisms are activated
to cool the body .
10. Which subatomic particle carries a positive charge and is found in the nucleus?
A) Electron
B) Neutron
C) Proton
D) Ion
Correct Answer: C
Rationale: Protons carry a positive charge and are located in the nucleus. Neutrons are neutral,
electrons are negatively charged and orbit the nucleus .
11. Isotopes of the same element differ in their number of:
A) Protons
B) Electrons
C) Neutrons
D) Ions
Correct Answer: C
Rationale: Isotopes are atoms of the same element that have the same number of protons but
different numbers of neutrons. This difference in neutron number affects atomic mass .
12. The valence shell of an atom refers to:
A) The innermost electron shell
B) The outermost electron shell
