Questions: is a condition that affects breathing and digestion due to thick mucus building up in the body, especially the lungs and digestive system. Cystic fibrosis Achondroplasia Tay-Sachs disease Phenylketonuria

The answer is the first one: Cystic fibrosis.

Explanation for each option:

1. Cystic fibrosis: This is the correct answer. Cystic fibrosis is a genetic disorder that affects the respiratory and digestive systems. It is characterized by the production of thick and sticky mucus that can clog the airways and lead to breathing difficulties, as well as block the ducts in the pancreas, affecting digestion.

2. Achondroplasia: This is incorrect. Achondroplasia is a form of short-limbed dwarfism. It affects bone growth, not the respiratory or digestive systems.

3. Tay-Sachs disease: This is incorrect. Tay-Sachs disease is a genetic disorder that affects the nervous system, leading to the destruction of nerve cells in the brain and spinal cord. It does not primarily affect breathing or digestion.

4. Phenylketonuria (PKU): This is incorrect. PKU is a metabolic disorder caused by a deficiency in the enzyme needed to process the amino acid phenylalanine. It can lead to intellectual disability if untreated but does not directly cause issues with breathing or digestion due to mucus buildup.

In summary, cystic fibrosis is the condition that affects breathing and digestion due to thick mucus building up in the body, particularly in the lungs and digestive system.