Correct statement with reference to a test-tube baby is

Options

A. the fertilised egg is placed in the womb of the mother where the gastrula period is completed
B. unfertilised egg is placed in the womb and allowed to grow parthenogenetically
C. a prematurely born baby is reared in an incubator
D. fertilised egg is taken out and grown in a large test-tube

Answer

### Step-by-Step Solution:

1. **Understanding Test-Tube Baby**: A test-tube baby refers to a child conceived through in vitro fertilization (IVF), where the fertilization of an egg by sperm occurs outside the human body, in a controlled laboratory environment.

2. **Process of IVF**: In this process, gametes (sperm and egg) are collected from the parents. These gametes are then combined in a specially prepared medium that provides all necessary conditions for fertilization.

3. **Formation of Zygote and Embryo**: After fertilization occurs, a zygote is formed. This zygote undergoes several divisions and develops into an embryo.

4. **Transfer to the Mother**: The embryo is then placed into the womb (uterus) of the mother, where it can implant and grow. This is where the gastrulation phase begins, leading to the development of the fetus.

5. **Evaluating the Options**:
- **Option 1**: "The fertilized egg is placed in the womb of the mother where the gastrula period is completed." This statement is correct as it accurately describes the process of placing the fertilized egg in the mother's womb for further development.
- **Option 2**: "The unfertilized egg is placed in the mother's womb and allowed to grow parthenogenetically." This is incorrect because humans do not reproduce parthenogenetically.
- **Option 3**: "A prematurely born baby is reared in an incubator." This is not relevant to the definition of a test-tube baby and is incorrect.
- **Option 4**: "Fertilized egg is taken out of the ground in a large test tube." This is misleading and incorrect, as fertilization occurs in a lab, not in the ground.

6. **Conclusion**: Based on the evaluation of the options, the correct statement regarding a test-tube baby is **Option 1**.