How does fertilisation take place in human beings? What changes will be exhibited after fertilisation?

Crossword puzzle

Down
1. Transfer of pollen grains from the anther to the stigma.
3. The muscular lower portion of the uterus.
5. The zygote develops into a baby here.
Across
2. A disc-like organ through which the embryo absorbs food and oxygen.
4. Female reproductive organ producing gamete, in both plants and animals.
6. The outermost whorl protecting the floral whorls in the bud stage.