Oestrogen is a hormone that is synthesized in the

1. Analyze the question The question asks where oestrogen, a female sex hormone, is made (synthesized).

2. Explain the concept Hormones are chemical messengers made by endocrine glands. Each gland makes specific hormones:

• Ovaries make oestrogen and progesterone. Within the ovary, the Graafian follicle cells make oestrogen, and the corpus luteum makes progesterone (and some oestrogen).
• Testes make testosterone.
• Anterior pituitary makes FSH, LH, growth hormone, prolactin, TSH and ACTH. FSH and LH stimulate the ovaries to make oestrogen, but the pituitary does not make oestrogen itself.
• Adrenal cortex makes corticosteroids such as cortisol and aldosterone, plus small amounts of sex steroids. It is not the main site of oestrogen synthesis.

3. Step-by-step solution

• Oestrogen is a female sex hormone, so we look for the female reproductive gland.
• Option B (testes) is the male gland, so it is out.
• Option C (anterior pituitary) makes the controlling hormones FSH and LH, not oestrogen.
• Option D (adrenal cortex) makes mainly corticosteroids, and only trace amounts of oestrogen.
• Option A (ovaries) is the primary site of oestrogen synthesis.

4. Answer A. ovaries

5. Exam tip Remember the link: FSH (pituitary) → follicle in the ovary → oestrogen. The pituitary gives the instruction, and the ovary makes the hormone. JAMB often tests this "which gland makes it vs. which gland controls it" distinction.