Question

Draw a flowchart to represent the process of oogenesis.

Hint:

Remember that the "arrest" points are crucial: Prophase I (from birth to puberty) and Metaphase II (until fertilization).

Answer 1

Flowchart for Oogenesis

Primordial Germ Cell
↓
Oogonium (2n)
• Undergoes mitotic divisions during fetal development
↓
Primary Oocyte (2n)
• Enters meiosis I and remains arrested in Prophase I until puberty
↓
Completion of Meiosis I (at puberty)
Primary oocyte divides unequally to form:
→ Secondary Oocyte (n)
→ First Polar Body (n)
↓
Secondary Oocyte
• Begins Meiosis II and remains arrested at Metaphase II
↓
If Fertilization Occurs
Meiosis II is completed
↓
Ovum (n)
+ Second Polar Body (n)
↓
Fusion with Sperm
↓
Zygote (2n)