The period of development is the time from conception to birth. (Watch your spelling!)

Prenatal period.

Explanation:

Two main types of reproduction that exist in living organisms are sexual reproduction and asexual reproduction. The fusion of the male and female gamete leads to the formation of zygote in case of sexual reproduction.

The prenatal period may be defined as the time development required for the fetal to grow in the womb. The prenatal period starts from the conception and remains till the birth of the child. Three main stages of prenatal period are germinal stage, embryonic stage and fetal stage.

Thus, the answer is prenatal period.

The prenatal period

Explanation:

The process of prenatal development occurs in three main stages.

- The first two weeks after conception are known as the germinal stage

- The third through the eighth week is known as the embryonic period, and

- The time from the ninth week until birth is known as the fetal period