Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow. 
Note : All plants belong to the same species. No pollen tube growth/inhibition of pollen germination on stigma. Pollen germination on stigma.
Answer the following questions:
[(i)] Explain the structure of a mature embryo sac of a typical flowering plant.
[(ii)] How is triple fusion achieved in these plants?
OR
[(i)] Describe the changes in the ovary and the uterus as induced by the changes in the level of pituitary and ovarian hormones during menstrual cycle in a human female.
The output (Y) of the given logic implementation is similar to the output of an/a …………. gate.
Fertilization happens when a sperm fuses with the female act during sexual intercourse and further forms an egg that gets implanted in the uterus of the female. The sperm goes through the fallopian tube and penetrates the zona pellucida layer of the ovum (female egg) and then fuses with it which forms a zygote (fertilized egg). Thousand of sperms are generated in a male body to compensate for the ones unfit and non-motile ones. Once the zygote is created or formed, it gets implanted in the uterus and further growth starts taking place when cells start dividing and forming tissues, and tissues further form organs which result in the formation of an organ system, eventually or in time turning into an organism.