the ovum is fertilized externally and thereafter implanted in the uterus
it develops from a non-fertilized uterus
Solution
Test tube baby is a method of in vitro fertilisation, which involves fertilizing an egg outside the body, in a laboratory dish, and then implanting it in a woman's uterus.
Related Theory
The only difference between a test tube baby and a normal baby is that test tube babies are born with the help of special fertility treatment, whereas normal babies born with the natural conception.