Secondary follicles contain a ___________ oocyte.

• A. secondary
• B. zygote
• C. mature (Graafian)
• D. primary

Answer: (D)

Verified step by step guidance

1. Understand the structure and development of ovarian follicles. Follicles are structures in the ovary that contain and nurture the developing oocyte (egg cell). They progress through several stages: primordial, primary, secondary, and mature (Graafian).
2. Recall that a secondary follicle is an intermediate stage in follicular development. It is characterized by the presence of multiple layers of granulosa cells and the formation of a fluid-filled cavity called the antrum.
3. Recognize that the type of oocyte present in a secondary follicle is still a primary oocyte. This is because the oocyte remains arrested in prophase I of meiosis during this stage of follicular development.
4. Differentiate between the stages of follicular development and the type of oocyte they contain. For example, a mature (Graafian) follicle contains a secondary oocyte, which has completed the first meiotic division and is arrested in metaphase II.
5. Conclude that secondary follicles contain a primary oocyte, as the oocyte has not yet completed the first meiotic division at this stage.