Question

cystic fibrosis is a genetic disorder that affects the lungs and digestive system, causing thick, sticky mucus to build up and make breathing and nutrient absorption difficult. it is usually caused by a mutation in the cftr gene, where three dna bases are taken away. this change disrupts the cftr proteins ability to move chloride ions across cell membranes, leading to the mucus buildup characteristic of the condition. what kind of mutation causes the disease cystic fibrosis?
hint: is it a substitution, insertion, or deletion

Explanation:

The question asks about the type of mutation causing Cystic Fibrosis. The text states that three DNA bases are taken away (deleted). In genetics, when a nucleotide (or in this case, three nucleotides) is removed from the DNA sequence, it is called a deletion mutation. Substitution would involve replacing a base, and insertion would involve adding a base. Since the key action here is removal (taking away), it's a deletion.

Answer:

Deletion mutation.