Test tube baby means a baby born when

Options

A. It develops from a non-fertilized egg
B. It developed in a test tube
C. It is developed through tissue culture method
D. The ovum is fertilised externally and thereafter implanted in the uterus

Explanation

**Step-by-Step Solution:**

1. **Definition of Test Tube Baby**: A test tube baby refers to a baby that is conceived through in vitro fertilization (IVF), where fertilization occurs outside the human body.

2. **Collection of Gametes**: The first step in the process involves collecting gametes (sperm from the male and eggs from the female) from the respective parents.

3. **Fertilization in Laboratory Conditions**: The collected gametes are then placed in a sterile laboratory environment, typically in a test tube or petri dish, where fertilization occurs. This is done by allowing the sperm to fertilize the egg.

4. **Development of Embryo**: After fertilization, the zygote begins to divide and develop into an embryo over the course of 3 to 4 days.

5. **Implantation in Uterus**: Once the embryo has developed sufficiently, it is then implanted into the uterus of the female parent, where it can continue to grow and develop into a baby.

6. **Conclusion**: Therefore, a test tube baby is one that is conceived through the external fertilization of an ovum, which is then implanted into the uterus.

**Final Answer**: A test tube baby means a baby born after the ovum is fertilized externally and then implanted in the uterus.

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