CBSE Class 9 Answered

The estrous cycle, seen in most mammals, allows the animals to place most of their mating energy into particular periods, and generally it is obvious to the males when females are in estrous. In some cases, estrus is limited to times that will allow birth when there are optimal environmental conditions for survival of the young, such as white-tailed deer mating in the autumn and giving birth in the spring. In contrast, the unique reproductive cycle of human beings, allowing sexual activity at any time and without overt external signs to signal estrual receptivity, fosters bonding between the male and female of a pair on the basis of sexual intimacy and love and facilitates overall social interactions in culture.