Which of these cells only exists in the fallopian tubes?
A - Oogonium
B - Secondary oocyte
C - Ovum
D - Primary oocyte
Answer: C - Ovum
Since the second meiotic division does not occur until fertilization, creation of the ovum only occurs at fertilization which happens in the fallopian tube, and very soon thereafter, the zygote begins cell division before it to the uterine wall, so the ovum is a very short-lived stage in oogenesis that only exists in the fallopian tubes. Secondary oocytes are found in the fallopian tubes, but they also exist in the ovaries just before ovulation.