1. Oviposition ability: The fertilized eggs of animals develop outside the mother's body and hatch into new individuals. Embryo development depends entirely on the yolk contained in the egg itself for nutrition.
2. viviparous: it is still oviparous in nature, because the nutrition of embryo development is still provided by yolk, not by the mother, but the process of fertilized egg development is carried out in the mother.
3. viviparous: viviparous refers to the reproductive mode in which the larvae of human beings or some animals develop to a certain stage in the mother before leaving the mother. The fertilized eggs of viviparous animals are generally very small, fertilized at the upper end of the mother's fallopian tube, and then developed into early embryos, which grow on the inner wall of the mother's uterus after being implanted in the uterus.
Through the connection between the placenta and the mother, the nutrients and oxygen in the mother's blood are absorbed, and carbon dioxide and waste are transported to the mother's blood and discharged through the mother. When the fetus matures, the uterus contracts to expel the larvae from the body, forming an independent new life.
Introduction of oviparous animals:
Birds, reptiles, most fish and insects are almost oviparous. For example, chickens, ducks, fish, frogs, turtles and butterflies are all egg-laying animals. After laying eggs, oviparous animals become animals after hatching, and their nutrition comes from the eggs themselves.
Introduction of viviparous animals:
Cone-toothed sharks, star sharks, some poisonous snakes (such as vipers and sea snakes), viviparous lizards and bronchus lizards are viviparous animals. This is a breeding mode formed by animals' long-term adaptation to bad environment, and the actual mother mainly plays the role of protecting and incubating embryos.
Introduction of viviparous animals:
Mammals: bats, seals, seals, dolphins, baboons, pangolins, mongooses, anteaters, sea otters, domestic animals, cats, rodents, primates, etc. Higher mammals in vertebrates, such as monkeys, tigers, cows, sheep and wolves, are viviparous.