Cystic Fibrosis Is Caused by a Mutation in the CFTR

question 65

Multiple Choice

Cystic fibrosis is caused by a mutation in the CFTR gene. The normal CFTR gene comprises approximately 190,000 nucleotides and produces an mRNA of 6128 nucleotides in length. What is a possible explanation for the difference in the sizes of the gene and the mRNA?

• A) The promoter of the CFTR gene is likely silenced by miRNAs prior to mRNA production.
• B) The CFTR gene likely has many introns that are excised prior to translation of the CFTR protein.
• C) The 5ʹ cap and the poly(A) tail get removed prior to translation of the CFTR protein.
• D) Methylation of the 5ʹ cap silences portions of the gene, preventing those regions from being transcribed into mRNA.
• E) The mutation that causes cystic fibrosis creates a new terminator sequence, resulting in a shorter mRNA.

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Definitions:

Conservation

Conservation is a cognitive ability to understand that quantities or properties remain consistent even when their form or appearance changes.

Intuitive Thought

A type of thinking that relies on instinctive processes rather than analytical reasoning.

Centration

A cognitive limitation in early child development, identified by Piaget, where the child focuses on one aspect of a situation, overlooking other relevant aspects.

Basic Cognitive Processes

Processes such as perception, memory, language, problem-solving, and abstract thinking that underlie all human behaviors and learning.