Essentials of Oral Histology and
Embryology, 6th Edition – Dental Exam
With correct answers and rationale
Chapter 1: Development and Structure of Cells and Tissues
1. Mitochondria produce which chemical for intracellular energy?
a. ADP
b. ATP
c. RNA
d. DNA
Rationale: Mitochondria generate energy through ATP production; ADP, RNA, and DNA are not the
energy currency produced by mitochondria-1.
2. Each tissue originates from mesoderm, EXCEPT one. Which is the EXCEPTION?
a. Bone
b. Liver
c. Blood
d. Muscle
Rationale: Liver tissue is produced by endodermal cells, while bone, blood, and muscle develop from
mesodermal cells-1.
3. Which chemical is called the second messenger?
a. cDNA
b. mRNA
c. dGMP
d. cAMP
Rationale: cAMP transmits information to intracellular organelles when activated by surface
receptors on the plasma membrane-1.
4. Which cellular component facilitates protein synthesis?
a. Ribosomes
b. Lysosomes
c. Mitochondria
d. Plasmalemma
Rationale: Ribosomes synthesize protein; lysosomes break down substances, mitochondria generate
energy, and the plasmalemma regulates transport-1.
5. Which organelle produces microtubules?
a. Nucleus
b. Centriole
c. Golgi apparatus
d. Endoplasmic reticulum
,Rationale: Centrioles produce microtubules; the other organelles listed do not perform this
function-1.
6. Which phase of the cell cycle is characterized as the initial resting stage?
a. G1 phase
b. S phase
c. G2 phase
d. M phase
Rationale: The G1 phase is the initial resting stage before DNA synthesis occurs-1.
7. Posttranslational modifications to proteins produced by the rough endoplasmic reticulum
occur in which organelle?
a. Golgi apparatus
b. Lysosome
c. Mitochondria
d. Nucleus
Rationale: The Golgi apparatus is critical for posttranslational modifications that sort, condense,
package, and deliver proteins from the ER.
8. Which type of bone formation occurs through a tight matrix of collagen fibers, which slowly
calcify into bone?
a. Endochondral
b. Intramembranous
c. Epiphyseal
d. Interstitial growth
Rationale: Intramembranous bone formation occurs through a tight matrix of collagen fibers that
slowly calcify, whereas endochondral bone replaces cartilage-17.
9. The cardiovascular system originates from which type of cells?
a. Chondroblasts
b. Angioblasts
c. Osteoblasts
d. Fibroblasts
Rationale: The cardiovascular system originates from angioblasts, not chondroblasts-17.
10. Tissues are most susceptible to teratogens during which period?
a. Embryonic period
b. Fetal period
c. Proliferative period
d. Postnatal period
Rationale: The embryonic period (weeks 2–8) is when tissues are most susceptible to teratogens due
to rapid differentiation.
Chapter 2: Structure and Function of Cells, Tissues, and Organs
11. Simple squamous epithelium functions as a lining in which location?
a. Mouth
, b. Vagina
c. Kidney
d. Pharynx
Rationale: The kidney is lined with simple squamous epithelium; the mouth, vagina, and pharynx are
lined with stratified squamous epithelium-17.
12. Which cell supports the nervous system?
a. Myoblast
b. Neuroglia
c. Leukocyte
d. Melanocyte
Rationale: Neuroglial cells support the nervous system; myoblasts form muscle, leukocytes are
immune cells, and melanocytes produce pigment-17.
13. Buccal mucosa renews itself in how many days?
a. 1 to 2
b. 3 to 4
c. 5 to 9
d. 10 to 14
Rationale: Buccal mucosa is replenished every 10 to 14 days-17.
14. The junctional epithelium of gingiva is replenished every how many days?
a. 1 to 3
b. 4 to 6
c. 7 to 9
d. 10 to 13
Rationale: Junctional epithelium renews every 4 to 6 days-17.
15. Which term represents a single layer of cells?
a. Simple
b. Stratified
c. Cuboidal
d. Columnar
Rationale: Simple epithelium consists of a single layer of cells; stratified refers to multiple layers-17.
16. Which type of epithelium has all cells in contact with the basal lamina, but not all reach the
surface?
a. Simple squamous
b. Stratified squamous
c. Pseudostratified
d. Transitional
Rationale: Pseudostratified epithelium has all cells in contact with the basal lamina, but not all reach
the surface-14.
17. Blood is a specialized connective tissue composed of formed elements suspended in:
a. Serum
b. Plasma
, c. Lymph
d. Interstitial fluid
Rationale: Blood consists of erythrocytes, leukocytes, and platelets suspended in plasma-14.
18. Which type of cartilage is found in the temporomandibular joint?
a. Hyaline cartilage
b. Elastic cartilage
c. Fibrous cartilage
d. Calcified cartilage
Rationale: Fibrous cartilage is found in the TMJ and intervertebral discs.
19. What is the primary function of the lymphatic system?
a. Oxygen transport
b. Immunologic defense
c. Hormone production
d. Temperature regulation
Rationale: The lymphatic system serves as a protective mechanism in immunologic defense,
destroying bacteria, viruses, and invasive microorganisms-14.
20. Which connective tissue cell type produces collagen fibers?
a. Osteoclast
b. Fibroblast
c. Chondroclast
d. Macrophage
Rationale: Fibroblasts are the primary cells responsible for producing collagen and other connective
tissue fibers.
Chapter 3: Development of the Oral Facial Region
21. The three periods of prenatal development are:
a. Proliferative, embryonic, fetal
b. Implantation, differentiation, maturation
c. Proliferative, embryonic, fetal
d. Fertilization, cleavage, implantation
Rationale: The three periods are proliferative (weeks 1–2), embryonic (weeks 2–8), and fetal (week 8
to birth)-10-14.
22. The proliferative period lasts approximately how long?
a. 1 week
b. 2 weeks
c. 4 weeks
d. 8 weeks
Rationale: The proliferative period lasts approximately 2 weeks and includes fertilization,
implantation, and formation of the embryonic disk-10.
Embryology, 6th Edition – Dental Exam
With correct answers and rationale
Chapter 1: Development and Structure of Cells and Tissues
1. Mitochondria produce which chemical for intracellular energy?
a. ADP
b. ATP
c. RNA
d. DNA
Rationale: Mitochondria generate energy through ATP production; ADP, RNA, and DNA are not the
energy currency produced by mitochondria-1.
2. Each tissue originates from mesoderm, EXCEPT one. Which is the EXCEPTION?
a. Bone
b. Liver
c. Blood
d. Muscle
Rationale: Liver tissue is produced by endodermal cells, while bone, blood, and muscle develop from
mesodermal cells-1.
3. Which chemical is called the second messenger?
a. cDNA
b. mRNA
c. dGMP
d. cAMP
Rationale: cAMP transmits information to intracellular organelles when activated by surface
receptors on the plasma membrane-1.
4. Which cellular component facilitates protein synthesis?
a. Ribosomes
b. Lysosomes
c. Mitochondria
d. Plasmalemma
Rationale: Ribosomes synthesize protein; lysosomes break down substances, mitochondria generate
energy, and the plasmalemma regulates transport-1.
5. Which organelle produces microtubules?
a. Nucleus
b. Centriole
c. Golgi apparatus
d. Endoplasmic reticulum
,Rationale: Centrioles produce microtubules; the other organelles listed do not perform this
function-1.
6. Which phase of the cell cycle is characterized as the initial resting stage?
a. G1 phase
b. S phase
c. G2 phase
d. M phase
Rationale: The G1 phase is the initial resting stage before DNA synthesis occurs-1.
7. Posttranslational modifications to proteins produced by the rough endoplasmic reticulum
occur in which organelle?
a. Golgi apparatus
b. Lysosome
c. Mitochondria
d. Nucleus
Rationale: The Golgi apparatus is critical for posttranslational modifications that sort, condense,
package, and deliver proteins from the ER.
8. Which type of bone formation occurs through a tight matrix of collagen fibers, which slowly
calcify into bone?
a. Endochondral
b. Intramembranous
c. Epiphyseal
d. Interstitial growth
Rationale: Intramembranous bone formation occurs through a tight matrix of collagen fibers that
slowly calcify, whereas endochondral bone replaces cartilage-17.
9. The cardiovascular system originates from which type of cells?
a. Chondroblasts
b. Angioblasts
c. Osteoblasts
d. Fibroblasts
Rationale: The cardiovascular system originates from angioblasts, not chondroblasts-17.
10. Tissues are most susceptible to teratogens during which period?
a. Embryonic period
b. Fetal period
c. Proliferative period
d. Postnatal period
Rationale: The embryonic period (weeks 2–8) is when tissues are most susceptible to teratogens due
to rapid differentiation.
Chapter 2: Structure and Function of Cells, Tissues, and Organs
11. Simple squamous epithelium functions as a lining in which location?
a. Mouth
, b. Vagina
c. Kidney
d. Pharynx
Rationale: The kidney is lined with simple squamous epithelium; the mouth, vagina, and pharynx are
lined with stratified squamous epithelium-17.
12. Which cell supports the nervous system?
a. Myoblast
b. Neuroglia
c. Leukocyte
d. Melanocyte
Rationale: Neuroglial cells support the nervous system; myoblasts form muscle, leukocytes are
immune cells, and melanocytes produce pigment-17.
13. Buccal mucosa renews itself in how many days?
a. 1 to 2
b. 3 to 4
c. 5 to 9
d. 10 to 14
Rationale: Buccal mucosa is replenished every 10 to 14 days-17.
14. The junctional epithelium of gingiva is replenished every how many days?
a. 1 to 3
b. 4 to 6
c. 7 to 9
d. 10 to 13
Rationale: Junctional epithelium renews every 4 to 6 days-17.
15. Which term represents a single layer of cells?
a. Simple
b. Stratified
c. Cuboidal
d. Columnar
Rationale: Simple epithelium consists of a single layer of cells; stratified refers to multiple layers-17.
16. Which type of epithelium has all cells in contact with the basal lamina, but not all reach the
surface?
a. Simple squamous
b. Stratified squamous
c. Pseudostratified
d. Transitional
Rationale: Pseudostratified epithelium has all cells in contact with the basal lamina, but not all reach
the surface-14.
17. Blood is a specialized connective tissue composed of formed elements suspended in:
a. Serum
b. Plasma
, c. Lymph
d. Interstitial fluid
Rationale: Blood consists of erythrocytes, leukocytes, and platelets suspended in plasma-14.
18. Which type of cartilage is found in the temporomandibular joint?
a. Hyaline cartilage
b. Elastic cartilage
c. Fibrous cartilage
d. Calcified cartilage
Rationale: Fibrous cartilage is found in the TMJ and intervertebral discs.
19. What is the primary function of the lymphatic system?
a. Oxygen transport
b. Immunologic defense
c. Hormone production
d. Temperature regulation
Rationale: The lymphatic system serves as a protective mechanism in immunologic defense,
destroying bacteria, viruses, and invasive microorganisms-14.
20. Which connective tissue cell type produces collagen fibers?
a. Osteoclast
b. Fibroblast
c. Chondroclast
d. Macrophage
Rationale: Fibroblasts are the primary cells responsible for producing collagen and other connective
tissue fibers.
Chapter 3: Development of the Oral Facial Region
21. The three periods of prenatal development are:
a. Proliferative, embryonic, fetal
b. Implantation, differentiation, maturation
c. Proliferative, embryonic, fetal
d. Fertilization, cleavage, implantation
Rationale: The three periods are proliferative (weeks 1–2), embryonic (weeks 2–8), and fetal (week 8
to birth)-10-14.
22. The proliferative period lasts approximately how long?
a. 1 week
b. 2 weeks
c. 4 weeks
d. 8 weeks
Rationale: The proliferative period lasts approximately 2 weeks and includes fertilization,
implantation, and formation of the embryonic disk-10.
