Question

In a human female, the reproductive phase starts on the onset of puberty and ceases around middle age of the female. Study the graph given below regarding menstrual cycle and answer the questions that follow: \begin{figure}[h!] \centering \includegraphics[width=0.8\textwidth]{Screenshot 2025-01-17 101211.png} % Replace 'path_to_your_image.png' with the actual path to your graph image \caption{Graph showing the hormonal regulation and events during the menstrual cycle.} \label{fig:menstrual_cycle} \end{figure} In a normal human female, why does menstruation only occur if the released ovum is not fertilised? Explain.}

Hint:

Menstruation occurs due to the absence of fertilisation, leading to hormonal changes and shedding of the uterine lining.

Answer 1

If the ovum is not fertilised, the corpus luteum degenerates, leading to a decline in progesterone levels. Low progesterone levels cause the breakdown of the endometrial lining, resulting in menstruation.