What type of development involves young obtaining nutrients directly from the mother and being born live?

The type of development where young obtain nutrients directly from the mother and are born live is known as viviparous development. In viviparous organisms, the embryos develop inside the mother's body, receiving nourishment through a placental connection or similar structure. This allows for a more complex form of development, as the young can grow in a controlled environment where they are protected and supplied with the necessary nutrients and oxygen. This method of reproduction is common in mammals, including humans, which further highlights the essential characteristics of viviparous development.

In contrast, oviparous species lay eggs that develop outside the mother's body, and ovoviviparous species produce eggs that hatch inside the mother's body but do not receive direct nourishment from her. External gestation, while it implies some form of gestation happening outside the mother, does not accurately capture the essence of direct nutrient transfer and live birth associated with viviparous development.