Which one of the following is least present in the endometrium during the proliferative phase of the menstrual cycle

Normally the gametes are disease free in human beings or even in other animals because

In man the foetal membrane which forms the intimate connection with the uterine tissue is

The figure given below illustrates the changes taking place during the human menstruation cycle

Identify hormones $A, B, C, D$ and $E$ from the figures

In the boxes shown in the figure write the name of the hormone (or hormones) controlling the stage in the human menstrual cycle

The ratio of the nucleus to cytoplasm at the beginning of cleavage is