IMAT - International Medical Admissions Molecular Genetics and Inheritance Questions and Answers

Question 1

A scientist analyzing a sample of DNA finds that it contains 28% adenine. Based on Chargaff's rules, what percentage of guanine should be present in this sample?

Accepted Answer

22%

Answer

28%

Answer

44%

Answer

56%

Question 2

In a dihybrid cross between two heterozygous individuals (AaBb), what is the expected phenotypic ratio of the offspring if the genes assort independently?

Accepted Answer

9:3:3:1

Answer

1:2:1

Answer

3:1

Answer

1:1:1:1

Question 3

A frameshift mutation is caused by which of the following events?

Accepted Answer

The insertion or deletion of one or more nucleotides.

Answer

A substitution of one nucleotide for another.

Answer

A mutation that changes an amino acid codon to a stop codon.

Answer

A mutation in a non-coding region of the DNA.

Question 4

In the lac operon of E. coli, what is the role of allolactose?

Accepted Answer

It functions as an inducer, inactivating the repressor protein.

Answer

It acts as a co-repressor, activating the repressor protein.

Answer

It binds to the operator, preventing transcription.

Answer

It binds to RNA polymerase, enhancing transcription.

Question 5

A man with type A blood and a woman with type B blood have a child with type O blood. What is the probability that their next child will have type AB blood?

Accepted Answer

25%

Answer

0%

Answer

50%

Answer

75%

Question 6

Which of the following processes occurs during transcription but NOT during DNA replication?

Accepted Answer

Incorporation of Uracil

Answer

Formation of a phosphodiester bond

Answer

Unwinding of the DNA double helix

Answer

Use of a polymerase enzyme