QB2 Genetics PASS

Below is a DNA sequence. Determine the RNA transcript until +9.

• 5’ – GCUAGCUAACGUAACG – 3’

• 5’ – AAUCGAUCG – 3’

• 5’ – GCUAGCUAA – 3’

• 5’ – CGAUCGAUU – 3’

• 5’ – AATCGATCG – 3’

Below is a diagram of a DNA molecule undergoing replication. The strand labelled with an asterisk (*) is the:

• Leading strand

• Template strand

• Lagging strand

• Leading strand and lagging strand

• Template strand and lagging strand

DNA polymerase DOES NOT require:

• Free 3’-COOH group

• Free deoxyribonucleotide triphosphates

• Template strand of DNA

• None of the above

If all organisms have the same genetic code, which statement is TRUE?

• The genetic code is not universal

• Amino acids from a dog and a human can be differentiated

• A single gene can potentially be expressed in all organisms

• DNA does not show degeneracy

The following mRNA sequence is translated. Using the table, determine the polypeptide sequence.

5' - AUG - UUC - GAU - AGC - AAA - UGA - 3'

• STOP–Phe–Ala–Ser–Lys–Met

• Phe–Asp–Ser–Leu–Met–STOP

• START–Phe–Asp–Ser–Lys–STOP

• START–Phe–Arg–Ser–Lys–STOP

The following mRNA sequence is being read by a ribosome: 5’–CCA-UCA–3’. Using the table below, which dipeptide will be formed?

• Proline–serine

• Glycine–serine

• Serine–Glycine

• Glycine–proline

If a phenotypic revertant with a back mutation is crossed with the wild-type,

• All progeny will have the wild-type genotype

• Some of the progeny will have a phenotype that is different from both the wild-type and mutant phenotypes

• Some of the progeny will have the mutant phenotype

• No progeny will be produced

Which of the following is most likely to have a harmful effect on an organism?

• A deletion of three nucleotides near the middle of a gene

• A base substitution near the end of the coding sequence

• A transition mutation

• A single nucleotide insertion close to the start of the coding sequence

• All of the above

In cystic fibrosis, there is a single codon deletion. What is the most likely consequence?

• Tautomeric shift

• Nonsense mutation

• Increased polypeptide chain length

• A protein missing an amino acid

Which statement is FALSE about DNA recombination?

• Occurs between non-homologous chromosomes

• Involves crossing over

• Described by the Holliday model

• Involves the formation of a chi structure intermediate