Which of the following cannot be detected in a developing foetus by amnicentesis ?

Options

A. Jaundice
B. Down's syndrome
C. Systic fibrosis
D. Colourblindness

Explanation

To solve the question "Which of the following cannot be detected in a developing fetus by amniocentesis?", we will follow these steps:

### Step 1: Understand Amniocentesis
Amniocentesis is a medical procedure used during pregnancy to extract amniotic fluid from the amniotic sac surrounding a developing fetus. This procedure is typically performed between the 14th and 16th week of pregnancy.

### Step 2: Identify the Purpose of Amniocentesis
The amniotic fluid contains fetal cells and substances that can be analyzed to detect genetic disorders and chromosomal anomalies. It can help identify conditions such as Down syndrome, cystic fibrosis, and other genetic disorders.

### Step 3: Analyze the Options
The options given are:
1. Jaundice
2. Down syndrome
3. Cystic fibrosis
4. Colour blindness

### Step 4: Determine Which Condition Cannot Be Detected
- **Jaundice**: This is a metabolic disorder that is usually caused by liver problems or other non-genetic factors. It is not a genetic disorder and cannot be detected through amniocentesis.
- **Down syndrome**: A genetic disorder caused by an extra chromosome, which can be detected through amniocentesis.
- **Cystic fibrosis**: A genetic disorder that affects the lungs and digestive system, detectable through amniocentesis.
- **Colour blindness**: A genetic condition that can also be identified through genetic testing in amniotic fluid.

### Conclusion
The condition that cannot be detected in a developing fetus by amniocentesis is **jaundice**.

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