NYUCD GENERAL EMBRYOLOGY EXAMINATION
COMPLETE QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE THIS YEAR JUST RELEASED
10-Point Exam Coverage
1. Gametogenesis
Spermatogenesis, oogenesis, meiosis, and chromosomal reduction.
2. Fertilization
Capacitation, acrosome reaction, fertilization process, and prevention of polyspermy.
3. Early Embryonic Development
Cleavage, morula, blastocyst formation, implantation, and bilaminar germ disc.
4. Gastrulation and Germ Layers
Formation of ectoderm, mesoderm, endoderm, primitive streak, and notochord.
5. Neurulation
Neural tube formation, neural crest cells, and associated congenital anomalies.
6. Organogenesis
Development of major organ systems including cardiovascular, respiratory, gastrointestinal,
urinary, reproductive, and nervous systems.
7. Craniofacial Development
Pharyngeal arches, facial prominences, palate formation, tongue development, and cranial
nerve associations.
8. Development of Teeth and Oral Structures
Tooth initiation, bud-cap-bell stages, enamel and dentin formation, eruption, and supporting
tissues.
9. Placenta and Fetal Membranes
Placental development, chorion, amnion, yolk sac, allantois, umbilical cord, and fetal circulation.
10. Congenital Anomalies and Teratology
Critical developmental periods, genetic disorders, environmental teratogens, cleft lip/palate,
neural tube defects, and developmental syndromes.
NYUCD General Embryology Examination
Question 1
Which statement most accurately describes the primary biological purpose of
meiosis during human gametogenesis before fertilization occurs?
,A. It doubles the chromosome number in germ cells before fertilization.
B. It produces genetically identical diploid daughter cells for tissue growth.
C. It reduces chromosome number by half while increasing genetic variation
among gametes.
D. It prevents crossing over between homologous chromosomes during cell
division.
Answer: C
Rationale: Meiosis produces haploid gametes while increasing genetic diversity
through crossing over and independent assortment.
Question 2
During normal human fertilization, which event immediately follows successful
penetration of the zona pellucida by the sperm cell?
A. Gastrulation begins.
B. Cortical granules are released to block polyspermy.
C. Implantation into the uterine wall occurs.
D. Neural tube closure is initiated.
Answer: B
Rationale: Cortical granule exocytosis modifies the zona pellucida, preventing
additional sperm from entering the oocyte.
Question 3
Which embryonic structure ultimately gives rise to nearly all tissues and organs
through differentiation into the three primary germ layers?
,A. Blastocyst cavity
B. Primitive streak
C. Trophoblast
D. Chorionic villus
Answer: B
Rationale: The primitive streak initiates gastrulation, producing ectoderm,
mesoderm, and endoderm.
Question 4
The trophoblast primarily contributes to which structure during early embryonic
development?
A. Neural tube
B. Placenta
C. Vertebral column
D. Somites
Answer: B
Rationale: The trophoblast differentiates into cytotrophoblast and
syncytiotrophoblast, essential components of the placenta.
Question 5
Which developmental stage is characterised by a solid ball of blastomeres formed
before the appearance of the blastocyst cavity?
A. Gastrula
, B. Morula
C. Zygote
D. Neurula
Answer: B
Rationale: The morula is a compact mass of approximately 16–32 blastomeres
preceding blastocyst formation.
Question 6
Which germ layer primarily forms the epithelial lining of the gastrointestinal tract
and associated digestive glands?
A. Ectoderm
B. Endoderm
C. Mesoderm
D. Neural crest
Answer: B
Rationale: Endoderm forms the epithelial lining of the digestive and respiratory
systems.
Question 7
Neural crest cells contribute extensively to which group of structures particularly
important in dental embryology?
A. Liver parenchyma
B. Craniofacial bones and connective tissues
COMPLETE QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE THIS YEAR JUST RELEASED
10-Point Exam Coverage
1. Gametogenesis
Spermatogenesis, oogenesis, meiosis, and chromosomal reduction.
2. Fertilization
Capacitation, acrosome reaction, fertilization process, and prevention of polyspermy.
3. Early Embryonic Development
Cleavage, morula, blastocyst formation, implantation, and bilaminar germ disc.
4. Gastrulation and Germ Layers
Formation of ectoderm, mesoderm, endoderm, primitive streak, and notochord.
5. Neurulation
Neural tube formation, neural crest cells, and associated congenital anomalies.
6. Organogenesis
Development of major organ systems including cardiovascular, respiratory, gastrointestinal,
urinary, reproductive, and nervous systems.
7. Craniofacial Development
Pharyngeal arches, facial prominences, palate formation, tongue development, and cranial
nerve associations.
8. Development of Teeth and Oral Structures
Tooth initiation, bud-cap-bell stages, enamel and dentin formation, eruption, and supporting
tissues.
9. Placenta and Fetal Membranes
Placental development, chorion, amnion, yolk sac, allantois, umbilical cord, and fetal circulation.
10. Congenital Anomalies and Teratology
Critical developmental periods, genetic disorders, environmental teratogens, cleft lip/palate,
neural tube defects, and developmental syndromes.
NYUCD General Embryology Examination
Question 1
Which statement most accurately describes the primary biological purpose of
meiosis during human gametogenesis before fertilization occurs?
,A. It doubles the chromosome number in germ cells before fertilization.
B. It produces genetically identical diploid daughter cells for tissue growth.
C. It reduces chromosome number by half while increasing genetic variation
among gametes.
D. It prevents crossing over between homologous chromosomes during cell
division.
Answer: C
Rationale: Meiosis produces haploid gametes while increasing genetic diversity
through crossing over and independent assortment.
Question 2
During normal human fertilization, which event immediately follows successful
penetration of the zona pellucida by the sperm cell?
A. Gastrulation begins.
B. Cortical granules are released to block polyspermy.
C. Implantation into the uterine wall occurs.
D. Neural tube closure is initiated.
Answer: B
Rationale: Cortical granule exocytosis modifies the zona pellucida, preventing
additional sperm from entering the oocyte.
Question 3
Which embryonic structure ultimately gives rise to nearly all tissues and organs
through differentiation into the three primary germ layers?
,A. Blastocyst cavity
B. Primitive streak
C. Trophoblast
D. Chorionic villus
Answer: B
Rationale: The primitive streak initiates gastrulation, producing ectoderm,
mesoderm, and endoderm.
Question 4
The trophoblast primarily contributes to which structure during early embryonic
development?
A. Neural tube
B. Placenta
C. Vertebral column
D. Somites
Answer: B
Rationale: The trophoblast differentiates into cytotrophoblast and
syncytiotrophoblast, essential components of the placenta.
Question 5
Which developmental stage is characterised by a solid ball of blastomeres formed
before the appearance of the blastocyst cavity?
A. Gastrula
, B. Morula
C. Zygote
D. Neurula
Answer: B
Rationale: The morula is a compact mass of approximately 16–32 blastomeres
preceding blastocyst formation.
Question 6
Which germ layer primarily forms the epithelial lining of the gastrointestinal tract
and associated digestive glands?
A. Ectoderm
B. Endoderm
C. Mesoderm
D. Neural crest
Answer: B
Rationale: Endoderm forms the epithelial lining of the digestive and respiratory
systems.
Question 7
Neural crest cells contribute extensively to which group of structures particularly
important in dental embryology?
A. Liver parenchyma
B. Craniofacial bones and connective tissues
