Question

Student to attempt either option (A) or (B):
(A) “A fully developed foetus initiates its delivery from the mother’s womb.” Explain.
OR
(B) Give reasons for the following:

• Why can a woman generally not conceive a child after 50 years of age?
• Polar bodies are formed during oogenesis and not during spermatogenesis.

Hint:

Delivery is triggered by oxytocin via foetal signals. Polar bodies form in oogenesis due to unequal divisions, unlike spermatogenesis.

Answer 1

(A) Step 1: A fully developed foetus sends signals to the maternal system through hormones.
Step 2: Foetal ejection reflex is triggered by mild uterine contractions.
Step 3: This stimulates the release of oxytocin from the maternal pituitary.
Step 4: Oxytocin enhances uterine contractions in a positive feedback loop until delivery occurs.
OR
(B) (i) After 50 years of age, a woman usually undergoes menopause, where the ovaries stop releasing eggs and hormonal support for conception ceases. (ii) During oogenesis, unequal cytoplasmic division occurs to preserve maximum cytoplasm in the ovum. The small, non-functional cells produced alongside are called polar bodies. In spermatogenesis, equal division produces four functional sperms, hence no polar bodies form.