Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into proteins.

Question 2

A mutation deletes a single amino acid from a protein. How many nucleotides must be deleted from the mRNA to cause this?

Accepted Answer

$$3$$

Question 3

Cystic fibrosis is most commonly caused by a deletion of phenylalanine at position 508 in the CFTR protein. What is the consequence of this mutation at the protein level?

Accepted Answer

The protein folds incorrectly and is destroyed by the cell.

Question 4

If an individual is heterozygous for the CFTR ∆F508 mutation (one wildtype allele and one mutant allele), what is the expected phenotype?

Accepted Answer

The individual will not develop cystic fibrosis symptoms.

Question 5

Which process is responsible for converting the information in DNA into mRNA?

Accepted Answer

Transcription

Question 6

How many copies of each gene are present in a typical human somatic cell?

Accepted Answer

$$2$$

Question 7

If two parents are both carriers (heterozygous) for the CFTR ∆F508 mutation, what is the probability that their child will have cystic fibrosis?

Accepted Answer

$$1/4$$

Question 8

Which of the following best explains why most disease-causing mutations in the CFTR gene are considered recessive?

Accepted Answer

They only cause a phenotype when present in two copies.

Question 9

A child inherits one wildtype CFTR allele and one ∆F508 allele. Which proteins will be produced in their cells?

Accepted Answer

Both functional and nonfunctional CFTR proteins

Question 10

Which of the following is a direct result of the central dogma in the context of cystic fibrosis?

Accepted Answer

A mutation in DNA leads to altered mRNA and a defective protein.

Question 11

Which step in the central dogma is responsible for the synthesis of proteins from mRNA?

Accepted Answer

Translation

Question 12

Which of the following best describes a dominant allele in the context of CFTR function?

Accepted Answer

It encodes a functional protein that is sufficient for normal phenotype.

Question 13

Which of the following scenarios best illustrates the concept of genotype determining phenotype?

Accepted Answer

A person with two mutant CFTR alleles develops cystic fibrosis.

Question 14

Which of the following is NOT a reason why disease severity in cystic fibrosis can vary among individuals with the same genotype?

Accepted Answer

The number of chromosomes in the cell

Question 15

Which of the following best describes the role of proteins in cells, as discussed in the course overview?

Accepted Answer

Proteins act as machines carrying out diverse cellular tasks.

Question 16

Which of the following is a real-world application of understanding the central dogma?

Accepted Answer

Predicting the outcome of genetic diseases based on DNA mutations.

Question 17

A genetic counselor is helping a couple, both carriers for the CFTR ∆F508 mutation, understand their risks. What fraction of their children are expected to be carriers?

Accepted Answer

$$1/2$$

Question 18

Which of the following best explains why few human phenotypes are simple single-gene traits?

Accepted Answer

Most traits are influenced by multiple genes and environmental factors.

Question 19

Which of the following is the correct sequence of events in gene expression?

Accepted Answer

DNA → Transcription → RNA → Translation → Protein

Question 20

A new gene therapy for sickle cell disease is approved. Which step in the central dogma is most directly targeted by gene therapy?

Accepted Answer

Altering the DNA sequence to correct the mutation

Genetics: Foundations, Central Dogma, and Cystic Fibrosis Case Study

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