What must happen for a hypothesis to become a theory?

When a hypothesis is proven by an experiment then it becomes theory.

If enough evidence accumulates to support a hypothesis, it moves to the next step — known as a theory in the scientific method and becomes accepted as a valid explanation of a phenomenon.

Hypothesis is constructed before any applicable research has been done. A theory, on the other hand, is supported by evidence.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.