Bio 253 Quiz 1 Exam (2026/2027) UPDATE Verified
Questions And Answers
Human Anatomy & Physiology I | Key Domains: Introduction to the Human Body (Organization,
Homeostasis), Chemistry for Biology (Biomolecules, Bonds), Cell Structure & Function, Tissues
(Epithelial, Connective, Muscular, Nervous), and Integumentary System | Expert-Aligned Structure |
Quiz-Ready Format
Introduction
This structured Bio 253 Quiz 1 for 2026/2027 provides a focused set of verified exam-style
questions with correct answers and rationales. It covers the foundational concepts of human
anatomy and physiology, emphasizing the chemical and cellular basis of life, tissue organization, and
the structure and function of the skin and its accessory organs.
Exam Structure:
• Quiz 1: (50 VERIFIED QUESTIONS)
Answer Format
All correct answers must appear in bold and cyan blue, accompanied by concise rationales
explaining the anatomical term, the physiological principle (e.g., negative feedback), the function of
a cellular organelle, the classification and location of a tissue type, and why alternative options are
structurally, chemically, or functionally incorrect.
Quiz 1 Questions
1. Which level of structural organization includes the heart, lungs, and stomach?
A. Cellular
, B. Tissue
C. Organ
D. Organ system
Correct Answer: C. Organ
Rationale: An organ is a structure composed of at least two tissue types that performs a specific
function. The heart, lungs, and stomach are all individual organs. Organ systems (D) include multiple
organs working together (e.g., cardiovascular system).
2. In a negative feedback loop that regulates body temperature, what is the role of the
hypothalamus?
A. Effector
B. Receptor
C. Control center
D. Stimulus
Correct Answer: C. Control center
Rationale: The hypothalamus integrates temperature information from receptors and initiates
responses (e.g., sweating or shivering) to maintain homeostasis, making it the control center. Receptors
(B) detect changes. Effectors (A) carry out responses. The stimulus (D) is the temperature change itself.
3. Which type of chemical bond involves the sharing of electrons between atoms?
A. Ionic bond
B. Hydrogen bond
, C. Covalent bond
D. Peptide bond
Correct Answer: C. Covalent bond
Rationale: Covalent bonds form when atoms share electrons to achieve stability. Ionic bonds (A)
involve electron transfer. Hydrogen bonds (B) are weak attractions between polar molecules. Peptide
bonds (D) are a specific type of covalent bond linking amino acids.
4. Which biomolecule is the primary source of quick energy for cellular processes?
A. Lipids
B. Proteins
C. Carbohydrates
D. Nucleic acids
Correct Answer: C. Carbohydrates
Rationale: Carbohydrates (especially glucose) are the body’s preferred and most immediate energy
source. Lipids (A) provide long-term energy storage. Proteins (B) are used for structure and enzymes,
not primary energy. Nucleic acids (D) store genetic information.
5. The plasma membrane is primarily composed of:
A. Phospholipid bilayer
B. Protein monolayer
C. Cholesterol crystals
D. Carbohydrate chains
Questions And Answers
Human Anatomy & Physiology I | Key Domains: Introduction to the Human Body (Organization,
Homeostasis), Chemistry for Biology (Biomolecules, Bonds), Cell Structure & Function, Tissues
(Epithelial, Connective, Muscular, Nervous), and Integumentary System | Expert-Aligned Structure |
Quiz-Ready Format
Introduction
This structured Bio 253 Quiz 1 for 2026/2027 provides a focused set of verified exam-style
questions with correct answers and rationales. It covers the foundational concepts of human
anatomy and physiology, emphasizing the chemical and cellular basis of life, tissue organization, and
the structure and function of the skin and its accessory organs.
Exam Structure:
• Quiz 1: (50 VERIFIED QUESTIONS)
Answer Format
All correct answers must appear in bold and cyan blue, accompanied by concise rationales
explaining the anatomical term, the physiological principle (e.g., negative feedback), the function of
a cellular organelle, the classification and location of a tissue type, and why alternative options are
structurally, chemically, or functionally incorrect.
Quiz 1 Questions
1. Which level of structural organization includes the heart, lungs, and stomach?
A. Cellular
, B. Tissue
C. Organ
D. Organ system
Correct Answer: C. Organ
Rationale: An organ is a structure composed of at least two tissue types that performs a specific
function. The heart, lungs, and stomach are all individual organs. Organ systems (D) include multiple
organs working together (e.g., cardiovascular system).
2. In a negative feedback loop that regulates body temperature, what is the role of the
hypothalamus?
A. Effector
B. Receptor
C. Control center
D. Stimulus
Correct Answer: C. Control center
Rationale: The hypothalamus integrates temperature information from receptors and initiates
responses (e.g., sweating or shivering) to maintain homeostasis, making it the control center. Receptors
(B) detect changes. Effectors (A) carry out responses. The stimulus (D) is the temperature change itself.
3. Which type of chemical bond involves the sharing of electrons between atoms?
A. Ionic bond
B. Hydrogen bond
, C. Covalent bond
D. Peptide bond
Correct Answer: C. Covalent bond
Rationale: Covalent bonds form when atoms share electrons to achieve stability. Ionic bonds (A)
involve electron transfer. Hydrogen bonds (B) are weak attractions between polar molecules. Peptide
bonds (D) are a specific type of covalent bond linking amino acids.
4. Which biomolecule is the primary source of quick energy for cellular processes?
A. Lipids
B. Proteins
C. Carbohydrates
D. Nucleic acids
Correct Answer: C. Carbohydrates
Rationale: Carbohydrates (especially glucose) are the body’s preferred and most immediate energy
source. Lipids (A) provide long-term energy storage. Proteins (B) are used for structure and enzymes,
not primary energy. Nucleic acids (D) store genetic information.
5. The plasma membrane is primarily composed of:
A. Phospholipid bilayer
B. Protein monolayer
C. Cholesterol crystals
D. Carbohydrate chains
