胎生

1. Origins, structure, and basic meaning

• Structure: 胎生 (reading たいせい) is a biological noun for viviparity, in which an embryo develops inside the mother and is born as live young.
• Basic usage: It is used to describe an animal’s reproductive mode and to contrast it with egg-laying reproduction.

2. Common pitfalls and similar expressions

• Classification, not one birth
  • 胎生の動物 characterizes the reproductive mode of an animal or group, not an individual birth event.
• Contrast with 卵生
  • 卵生 involves development in an egg laid outside the body; 胎生 involves internal development followed by live birth.