Which is the phase characterized by major growth and development of the fetus?

The phase characterized by major growth and development of the fetus is the fetal development stage. This phase occurs after the embryonic stage, beginning at approximately 9 weeks of gestation and continuing until birth. During fetal development, the organism undergoes significant physical growth and morphological changes. Essential developments include the formation of organs and systems, rapid increases in size, and more refined structural features.

In this stage, the fetus not only gains weight and size but also undergoes critical developments such as the maturation of the central nervous system, the lungs, and other vital organs, preparing the fetus for life outside the womb. The growth in this stage is marked by the increase in complexity and functionality of these organs, which are crucial for survival after delivery.

Other stages mentioned, such as embryonic development, focus more on the early formation of basic structures and organ systems, while the germinal stage involves initial cell division and implantation. Ovulation refers to the release of an egg and does not pertain to fetal growth or development. Therefore, fetal development is clearly the phase associated with substantive and vital growth of the fetus itself.