As a flower develops, which transition is most likely to occur?

Question

Quizplus · Accepted Answer

The development of pollen grains from microspores is a key transition in the lifecycle of a flower as it enables the process of pollination and fertilization to occur. This transition typically occurs early in the development of the flower, before the ovule becomes a fruit and before the petals have fully formed. The vegetative nucleus becoming a sperm nucleus is also an important transition, but it occurs later in the process of pollination and fertilization. Retention of petals is not a significant transition in the development of a flower.

As a Flower Develops, Which Transition Is Most Likely to Occur