Which statement about cystic fibrosis is true? (1 point)
A. • Carriers have an advantage over people who do not have the cystic fibrosis mutation.
B. • Cystic fibrosis is caused by a deletion of one codon in the DNA molecule.
C. • Cystic fibrosis is caused by a mutation in which a dominant allele replaces a recessive allele.
D. • Cystic fibrosis affects a person's ability to make normal red blood cells.
D. • Cystic fibrosis affects a person's ability to make normal red blood cells.
The statement that is true about cystic fibrosis is:
C. Cystic fibrosis is caused by a mutation in which a dominant allele replaces a recessive allele.
To determine which statement about cystic fibrosis is true, we need to evaluate each option and understand the characteristics of cystic fibrosis.
A. Carriers have an advantage over people who do not have the cystic fibrosis mutation:
This statement is not true. Carriers of the cystic fibrosis gene may not exhibit symptoms of the condition, but they do not have an advantage over people without the mutation. In fact, individuals who inherit two copies of the mutated gene, one from each parent, develop cystic fibrosis.
B. Cystic fibrosis is caused by a deletion of one codon in the DNA molecule:
This statement is not entirely accurate. Cystic fibrosis is caused by a mutation in the CFTR gene, which leads to the production of a faulty or absent CFTR protein. While the specific mutation can vary, it is not limited to the deletion of a single codon.
C. Cystic fibrosis is caused by a mutation in which a dominant allele replaces a recessive allele:
This statement is not true. Cystic fibrosis is an autosomal recessive genetic disorder, meaning that it occurs when an individual inherits two copies of the mutated gene, one from each parent. The mutation is not dominant, and it does not replace a recessive allele.
D. Cystic fibrosis affects a person's ability to make normal red blood cells:
This statement is not accurate. Cystic fibrosis primarily affects the respiratory and digestive systems, leading to the production of thick, sticky mucus that can obstruct the airways, pancreas, and other organs. It does not directly impact a person's ability to produce normal red blood cells.
Therefore, none of the statements provided (A, B, C, D) is true regarding cystic fibrosis.