WGU D312 ANATOMY AND PHYSIOLOGY I
OBJECTIVE ASSESSMENT ACTUAL EXAM 2025-
2026 QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES || 100%
GUARANTEED PASS <RECENT VERSION>
WGU D312 Anatomy & Physiology I: 100 QA with Rationales
Cell Biology and Tissues
1. What is the primary function of the ribosomes?
A) Lipid synthesis
B) Protein synthesis (✓)
C) ATP production
D) Detoxification
Rationale: Ribosomes, whether free in the cytoplasm or bound to the rough
endoplasmic reticulum, are the sites of protein synthesis, where mRNA is translated into
polypeptide chains.
2. Which organelle is responsible for packaging proteins into vesicles for transport?
A) Golgi Apparatus (✓)
B) Mitochondria
C) Nucleolus
D) Smooth Endoplasmic Reticulum
Rationale: The Golgi apparatus modifies, sorts, and packages proteins received from the
rough ER into vesicles for secretion or delivery to other organelles.
3. During which phase of the cell cycle does DNA replication occur?
A) G1 Phase
B) S Phase (✓)
C) G2 Phase
D) Mitosis
Rationale: The S (Synthesis) Phase is dedicated to the replication of DNA, ensuring that
each daughter cell will receive a complete set of genetic information.
,4. A solution that has a higher concentration of solutes than the cell's cytoplasm is called:
A) Isotonic
B) Hypotonic
C) Hypertonic (✓)
D) Osmotic
Rationale: In a hypertonic solution, water leaves the cell by osmosis, causing the cell to
shrivel (crenate).
5. Which type of tissue is specialized for the conduction of electrical impulses?
A) Muscle Tissue
B) Epithelial Tissue
C) Connective Tissue
D) Nervous Tissue (✓)
Rationale: Nervous tissue, composed of neurons and neuroglia, is excitable and
specialized for generating and transmitting nerve impulses.
6. What type of epithelial tissue forms the lining of the air sacs in the lungs and permits
rapid diffusion?
A) Stratified Squamous Epithelium
B) Simple Columnar Epithelium
C) Simple Squamous Epithelium (✓)
D) Pseudostratified Ciliated Columnar Epithelium
Rationale: Simple squamous epithelium is a single layer of flat cells, ideal for sites of
filtration and diffusion, such as the alveoli of the lungs.
7. Glands that secrete their products (like hormones) directly into the blood are classified
as:
A) Exocrine Glands
B) Endocrine Glands (✓)
C) Merocrine Glands
D) Apocrine Glands
Rationale: Endocrine glands are ductless and release their secretions (hormones) into
the extracellular fluid, which then diffuses into the bloodstream.
8. The matrix of blood tissue is called:
A) Plasma (✓)
B) Interstitial Fluid
C) Cytosol
D) Lymph
, Rationale: Blood is a fluid connective tissue. Its extracellular matrix is the liquid plasma,
in which the formed elements (red blood cells, white blood cells, platelets) are
suspended.
Integumentary System
9. The layer of the epidermis where cells begin the process of keratinization is the:
A) Stratum Basale
B) Stratum Spinosum
C) Stratum Granulosum (✓)
D) Stratum Corneum
Rationale: In the stratum granulosum, cells fill with keratin granules (keratohyalin) and
their nuclei begin to degenerate, marking the start of keratinization.
10. What is the primary function of melanin?
A) To provide waterproofing
B) To provide vitamin D synthesis
C) To protect against UV radiation (✓)
D) To regulate body temperature
Rationale: Melanin is a pigment produced by melanocytes that absorbs harmful
ultraviolet (UV) radiation, protecting the DNA in skin cells from damage.
11. Which layer of the skin contains blood vessels, nerves, and hair follicles?
A) Epidermis
B) Dermis (✓)
C) Hypodermis
D) Stratum Corneum
Rationale: The dermis is the thick, vascular layer of connective tissue deep to the
epidermis. It contains nerves, blood vessels, sweat and oil glands, and hair follicles.
12. Sweat glands that are activated during emotional stress (fear, anxiety) are:
A) Eccrine Glands
B) Apocrine Glands (✓)
C) Sebaceous Glands
D) Ceruminous Glands
Rationale: Apocrine sweat glands, found in axillary and genital regions, secrete a milky
protein-rich sweat that is activated by emotional stress and sexual foreplay.
Skeletal System
, 13. Which bone cell is responsible for bone resorption (breakdown)?
A) Osteoblast
B) Osteocyte
C) Osteoclast (✓)
D) Osteogenic Cell
Rationale: Osteoclasts are large, multinucleated cells that secrete acids and enzymes to
break down bone matrix, releasing calcium into the blood.
14. The foramen magnum is a feature of which bone?
A) Parietal Bone
B) Temporal Bone
C) Sphenoid Bone
D) Occipital Bone (✓)
Rationale: The foramen magnum is the large opening in the base of the occipital bone
through which the spinal cord connects to the brainstem.
15. The structural unit of compact bone is the:
A) Trabecula
B) Lacunae
C) Osteon (Haversian system) (✓)
D) Canaliculi
Rationale: An osteon is a central canal (Haversian canal) surrounded by concentric rings
(lamellae) of bone matrix, making up the fundamental functional unit of compact bone.
16. Which type of joint is immovable, such as the sutures of the skull?
A) Synarthrosis (✓)
B) Amphiarthrosis
C) Diarthrosis
D) Synovial
Rationale: Synarthrosis joints are immovable joints. Fibrous joints like skull sutures are
classic examples.
17. The "soft spots" on an infant's skull, composed of fibrous membranes, are called:
A) Sinuses
B) Foramina
C) Fontanelles (✓)
D) Fissures
Rationale: Fontanelles are fibrous membranes connecting cranial bones in an infant,
allowing for skull deformation during birth and rapid brain growth.
OBJECTIVE ASSESSMENT ACTUAL EXAM 2025-
2026 QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES || 100%
GUARANTEED PASS <RECENT VERSION>
WGU D312 Anatomy & Physiology I: 100 QA with Rationales
Cell Biology and Tissues
1. What is the primary function of the ribosomes?
A) Lipid synthesis
B) Protein synthesis (✓)
C) ATP production
D) Detoxification
Rationale: Ribosomes, whether free in the cytoplasm or bound to the rough
endoplasmic reticulum, are the sites of protein synthesis, where mRNA is translated into
polypeptide chains.
2. Which organelle is responsible for packaging proteins into vesicles for transport?
A) Golgi Apparatus (✓)
B) Mitochondria
C) Nucleolus
D) Smooth Endoplasmic Reticulum
Rationale: The Golgi apparatus modifies, sorts, and packages proteins received from the
rough ER into vesicles for secretion or delivery to other organelles.
3. During which phase of the cell cycle does DNA replication occur?
A) G1 Phase
B) S Phase (✓)
C) G2 Phase
D) Mitosis
Rationale: The S (Synthesis) Phase is dedicated to the replication of DNA, ensuring that
each daughter cell will receive a complete set of genetic information.
,4. A solution that has a higher concentration of solutes than the cell's cytoplasm is called:
A) Isotonic
B) Hypotonic
C) Hypertonic (✓)
D) Osmotic
Rationale: In a hypertonic solution, water leaves the cell by osmosis, causing the cell to
shrivel (crenate).
5. Which type of tissue is specialized for the conduction of electrical impulses?
A) Muscle Tissue
B) Epithelial Tissue
C) Connective Tissue
D) Nervous Tissue (✓)
Rationale: Nervous tissue, composed of neurons and neuroglia, is excitable and
specialized for generating and transmitting nerve impulses.
6. What type of epithelial tissue forms the lining of the air sacs in the lungs and permits
rapid diffusion?
A) Stratified Squamous Epithelium
B) Simple Columnar Epithelium
C) Simple Squamous Epithelium (✓)
D) Pseudostratified Ciliated Columnar Epithelium
Rationale: Simple squamous epithelium is a single layer of flat cells, ideal for sites of
filtration and diffusion, such as the alveoli of the lungs.
7. Glands that secrete their products (like hormones) directly into the blood are classified
as:
A) Exocrine Glands
B) Endocrine Glands (✓)
C) Merocrine Glands
D) Apocrine Glands
Rationale: Endocrine glands are ductless and release their secretions (hormones) into
the extracellular fluid, which then diffuses into the bloodstream.
8. The matrix of blood tissue is called:
A) Plasma (✓)
B) Interstitial Fluid
C) Cytosol
D) Lymph
, Rationale: Blood is a fluid connective tissue. Its extracellular matrix is the liquid plasma,
in which the formed elements (red blood cells, white blood cells, platelets) are
suspended.
Integumentary System
9. The layer of the epidermis where cells begin the process of keratinization is the:
A) Stratum Basale
B) Stratum Spinosum
C) Stratum Granulosum (✓)
D) Stratum Corneum
Rationale: In the stratum granulosum, cells fill with keratin granules (keratohyalin) and
their nuclei begin to degenerate, marking the start of keratinization.
10. What is the primary function of melanin?
A) To provide waterproofing
B) To provide vitamin D synthesis
C) To protect against UV radiation (✓)
D) To regulate body temperature
Rationale: Melanin is a pigment produced by melanocytes that absorbs harmful
ultraviolet (UV) radiation, protecting the DNA in skin cells from damage.
11. Which layer of the skin contains blood vessels, nerves, and hair follicles?
A) Epidermis
B) Dermis (✓)
C) Hypodermis
D) Stratum Corneum
Rationale: The dermis is the thick, vascular layer of connective tissue deep to the
epidermis. It contains nerves, blood vessels, sweat and oil glands, and hair follicles.
12. Sweat glands that are activated during emotional stress (fear, anxiety) are:
A) Eccrine Glands
B) Apocrine Glands (✓)
C) Sebaceous Glands
D) Ceruminous Glands
Rationale: Apocrine sweat glands, found in axillary and genital regions, secrete a milky
protein-rich sweat that is activated by emotional stress and sexual foreplay.
Skeletal System
, 13. Which bone cell is responsible for bone resorption (breakdown)?
A) Osteoblast
B) Osteocyte
C) Osteoclast (✓)
D) Osteogenic Cell
Rationale: Osteoclasts are large, multinucleated cells that secrete acids and enzymes to
break down bone matrix, releasing calcium into the blood.
14. The foramen magnum is a feature of which bone?
A) Parietal Bone
B) Temporal Bone
C) Sphenoid Bone
D) Occipital Bone (✓)
Rationale: The foramen magnum is the large opening in the base of the occipital bone
through which the spinal cord connects to the brainstem.
15. The structural unit of compact bone is the:
A) Trabecula
B) Lacunae
C) Osteon (Haversian system) (✓)
D) Canaliculi
Rationale: An osteon is a central canal (Haversian canal) surrounded by concentric rings
(lamellae) of bone matrix, making up the fundamental functional unit of compact bone.
16. Which type of joint is immovable, such as the sutures of the skull?
A) Synarthrosis (✓)
B) Amphiarthrosis
C) Diarthrosis
D) Synovial
Rationale: Synarthrosis joints are immovable joints. Fibrous joints like skull sutures are
classic examples.
17. The "soft spots" on an infant's skull, composed of fibrous membranes, are called:
A) Sinuses
B) Foramina
C) Fontanelles (✓)
D) Fissures
Rationale: Fontanelles are fibrous membranes connecting cranial bones in an infant,
allowing for skull deformation during birth and rapid brain growth.
