Zygote Cleavage in the Oviduct

Steps:

• Fertilization occurs in the oviduct when sperm meets the egg, forming a zygote.
• The zygote begins mitotic divisions, called cleavage, shortly after formation.
• These divisions create a morula, a ball of cells, while traveling through the oviduct.
• The morula then reaches the uterus for implantation.

Why C is correct:

• The oviduct (fallopian tube) is where fertilization happens, and by definition, zygote cleavage starts there as it moves toward the uterus.

Why the others are wrong:

• A. Cervix: Narrow passage connecting vagina to uterus; no role in early zygote division.
• B. Ovary: Produces eggs; fertilization and division occur post-ovulation in the oviduct.
• D. Uterus: Site of implantation after cleavage; zygote arrives as a morula or blastocyst.

Final answer: C