EXAM: OOGENESIS & FOLLICULOGENESIS
TABLE OF CONTENTS
Section Title Question Numbers
A Fundamentals & Primordial Germ Cells 1 – 20
B Meiosis & Crossing Over 21 – 40
C Folliculogenesis – Primordial to Preantral 41 – 65
D Antral & Graafian Follicles 66 – 85
E Corpus Luteum & Luteolysis 86 – 100
F Clinical Correlations 101 – 129
Detailed Subtopics per Section
Section A (Qs 1–20)
• Origin and migration of primordial germ cells
• Oogonia proliferation and transition to primary oocytes
• Meiotic arrest (diplotene/dictyate stage)
• Fetal ovarian development and atresia
• Key genes (BLIMP1, c-KIT/SCF, NOBOX, WNT4)
Section B (Qs 21–40)
• Prophase I substages and synaptonemal complex
• Crossing over and chiasmata
• Meiotic arrest, resumption (LH surge, MPF, cAMP)
• Polar body formation, aneuploidy, cohesin aging
• Cytostatic factor (CSF) and metaphase II arrest
,Section C (Qs 41–65)
• Primordial follicle activation (KITL, PI3K pathway)
• Transition to primary and secondary follicles
• Zona pellucida composition, transzonal projections
• Theca cell differentiation (two-cell/two-gonadotropin)
• Oocyte-secreted factors (GDF9, BMP15) and AMH
Section D (Qs 66–85)
• Antrum formation and follicular fluid
• Cumulus oophorus and corona radiata
• Follicular dominance and selection
• LH surge: meiosis resumption, cumulus expansion
• Ovulation (proteases, prostaglandins)
Section E (Qs 86–100)
• Corpus luteum formation and luteinization
• Progesterone secretion and luteal phase
• Luteolysis (PGF2α, declining LH)
• Rescue by hCG in pregnancy
• Corpus albicans and clinical luteal phase defect
Section F (Qs 101–129)
• Primary ovarian insufficiency (POI) – Turner, Fragile X
• Hypogonadotropic hypogonadism (Kallmann)
• PCOS, OHSS, ovarian reserve testing (AMH, AFC)
• Ovarian tumors (granulosa cell, teratoma)
• Aneuploidy, PGT-A, oocyte cryopreservation, IVM
• Two-cell/two-gonadotropin theory, anovulation causes
• Fertilization (calcium oscillations, cortical reaction)
• Imprinting, parthenogenesis, future fertility options
SECTION A: FUNDAMENTALS & PRIMORDIAL GERM CELLS
(Questions 1–20)
1. The process of oogenesis begins during which developmental stage?
A) Fetal period
,B) Neonatal period
C) Puberty
D) Every menstrual cycle
E) Fertilization
Answer: A) Fetal period
Rationale: Oogenesis initiates in the fetal ovaries with the proliferation of
primordial germ cells and entry into meiosis I, arresting at prophase I before birth.
2. Primordial germ cells (PGCs) originate from:
A) Yolk sac endoderm
B) Mesonephric duct
C) Neural crest
D) Extraembryonic mesoderm
E) Intermediate mesoderm
Answer: A) Yolk sac endoderm
Rationale: PGCs are first identifiable in the wall of the yolk sac near the allantois
and migrate via the dorsal mesentery to the genital ridges.
3. Which transcription factor is essential for PGC specification and survival?
A) SRY
B) SOX9
C) BLIMP1 (PRDM1)
D) FOXL2
E) WNT4
Answer: C) BLIMP1 (PRDM1)
Rationale: BLIMP1 represses somatic differentiation genes and maintains the germ
cell fate; PRDM14 and TFAP2C are also critical.
4. Migration of PGCs to the genital ridge is guided by:
A) Fibronectin and laminin
B) c-KIT/SCF signaling
C) BMP4 gradients
D) Retinoic acid
E) Testosterone
Answer: B) c-KIT/SCF signaling
Rationale: Steel factor (SCF) from the genital ridge binds c-KIT on PGCs,
promoting survival and directed migration.
, 5. True/False: PGCs undergo genomic imprinting erasure before arriving at the
genital ridge.
Answer: True
Rationale: Primordial germ cells erase existing imprinting marks around E8–E10
in mice (week 4–6 in humans) to establish sex-specific imprints later.
6. The number of PGCs at the peak of migration is approximately:
A) 100
B) 1,000
C) 10,000
D) 100,000
E) 1 million
Answer: C) 10,000
Rationale: After proliferation during migration, about 10,000 PGCs colonize each
genital ridge in humans.
7. Which structure do PGCs use as a migratory scaffold?
A) Wolffian duct
B) Dorsal mesentery
C) Urogenital sinus
D) Cloacal membrane
E) Allantois
Answer: B) Dorsal mesentery
Rationale: PGCs travel through the hindgut endoderm and then along the dorsal
mesentery to reach the gonadal ridges.
8. Mitotic expansion of oogonia occurs within:
A) Medulla of the ovary
B) Cortex of the ovary
C) Hilum
D) Rete ovarii
E) Follicular antrum
Answer: B) Cortex of the ovary
Rationale: Oogonia proliferate by mitosis in the ovarian cortex, forming clusters
connected by intercellular bridges.
9. The transition from oogonia to primary oocytes is marked by:
A) Completion of meiosis II
TABLE OF CONTENTS
Section Title Question Numbers
A Fundamentals & Primordial Germ Cells 1 – 20
B Meiosis & Crossing Over 21 – 40
C Folliculogenesis – Primordial to Preantral 41 – 65
D Antral & Graafian Follicles 66 – 85
E Corpus Luteum & Luteolysis 86 – 100
F Clinical Correlations 101 – 129
Detailed Subtopics per Section
Section A (Qs 1–20)
• Origin and migration of primordial germ cells
• Oogonia proliferation and transition to primary oocytes
• Meiotic arrest (diplotene/dictyate stage)
• Fetal ovarian development and atresia
• Key genes (BLIMP1, c-KIT/SCF, NOBOX, WNT4)
Section B (Qs 21–40)
• Prophase I substages and synaptonemal complex
• Crossing over and chiasmata
• Meiotic arrest, resumption (LH surge, MPF, cAMP)
• Polar body formation, aneuploidy, cohesin aging
• Cytostatic factor (CSF) and metaphase II arrest
,Section C (Qs 41–65)
• Primordial follicle activation (KITL, PI3K pathway)
• Transition to primary and secondary follicles
• Zona pellucida composition, transzonal projections
• Theca cell differentiation (two-cell/two-gonadotropin)
• Oocyte-secreted factors (GDF9, BMP15) and AMH
Section D (Qs 66–85)
• Antrum formation and follicular fluid
• Cumulus oophorus and corona radiata
• Follicular dominance and selection
• LH surge: meiosis resumption, cumulus expansion
• Ovulation (proteases, prostaglandins)
Section E (Qs 86–100)
• Corpus luteum formation and luteinization
• Progesterone secretion and luteal phase
• Luteolysis (PGF2α, declining LH)
• Rescue by hCG in pregnancy
• Corpus albicans and clinical luteal phase defect
Section F (Qs 101–129)
• Primary ovarian insufficiency (POI) – Turner, Fragile X
• Hypogonadotropic hypogonadism (Kallmann)
• PCOS, OHSS, ovarian reserve testing (AMH, AFC)
• Ovarian tumors (granulosa cell, teratoma)
• Aneuploidy, PGT-A, oocyte cryopreservation, IVM
• Two-cell/two-gonadotropin theory, anovulation causes
• Fertilization (calcium oscillations, cortical reaction)
• Imprinting, parthenogenesis, future fertility options
SECTION A: FUNDAMENTALS & PRIMORDIAL GERM CELLS
(Questions 1–20)
1. The process of oogenesis begins during which developmental stage?
A) Fetal period
,B) Neonatal period
C) Puberty
D) Every menstrual cycle
E) Fertilization
Answer: A) Fetal period
Rationale: Oogenesis initiates in the fetal ovaries with the proliferation of
primordial germ cells and entry into meiosis I, arresting at prophase I before birth.
2. Primordial germ cells (PGCs) originate from:
A) Yolk sac endoderm
B) Mesonephric duct
C) Neural crest
D) Extraembryonic mesoderm
E) Intermediate mesoderm
Answer: A) Yolk sac endoderm
Rationale: PGCs are first identifiable in the wall of the yolk sac near the allantois
and migrate via the dorsal mesentery to the genital ridges.
3. Which transcription factor is essential for PGC specification and survival?
A) SRY
B) SOX9
C) BLIMP1 (PRDM1)
D) FOXL2
E) WNT4
Answer: C) BLIMP1 (PRDM1)
Rationale: BLIMP1 represses somatic differentiation genes and maintains the germ
cell fate; PRDM14 and TFAP2C are also critical.
4. Migration of PGCs to the genital ridge is guided by:
A) Fibronectin and laminin
B) c-KIT/SCF signaling
C) BMP4 gradients
D) Retinoic acid
E) Testosterone
Answer: B) c-KIT/SCF signaling
Rationale: Steel factor (SCF) from the genital ridge binds c-KIT on PGCs,
promoting survival and directed migration.
, 5. True/False: PGCs undergo genomic imprinting erasure before arriving at the
genital ridge.
Answer: True
Rationale: Primordial germ cells erase existing imprinting marks around E8–E10
in mice (week 4–6 in humans) to establish sex-specific imprints later.
6. The number of PGCs at the peak of migration is approximately:
A) 100
B) 1,000
C) 10,000
D) 100,000
E) 1 million
Answer: C) 10,000
Rationale: After proliferation during migration, about 10,000 PGCs colonize each
genital ridge in humans.
7. Which structure do PGCs use as a migratory scaffold?
A) Wolffian duct
B) Dorsal mesentery
C) Urogenital sinus
D) Cloacal membrane
E) Allantois
Answer: B) Dorsal mesentery
Rationale: PGCs travel through the hindgut endoderm and then along the dorsal
mesentery to reach the gonadal ridges.
8. Mitotic expansion of oogonia occurs within:
A) Medulla of the ovary
B) Cortex of the ovary
C) Hilum
D) Rete ovarii
E) Follicular antrum
Answer: B) Cortex of the ovary
Rationale: Oogonia proliferate by mitosis in the ovarian cortex, forming clusters
connected by intercellular bridges.
9. The transition from oogonia to primary oocytes is marked by:
A) Completion of meiosis II
