Question

The germination of embryo occurs normally when fruit is still attached to plant

Answer 1

When a seed germinates and starts growing (till some stage of life) while still attached to the mother plant, it is called as Vivipary. In many cases it is a mechanism that allows seeds to germinate in harsh/unfavorable contidions.

In many mangrove species, vivipary is seen. The mangroves grow along the water-land interface, thus the seeds would not germinate if submerged all the time. The seeds germinate on plant and propahules fall off around the time where they can float on water and develop into a new plant once they reach land.