2018_Euk-Gene-Exp_Organisation_Control_MCQ_QP+MS

2018 Gene Expression, Organisation and Control MCQ 2018 / H2 / ACJC PRELIM / P1 Q101Which statement(s) about DNA polymerases and RNA polymerases is/ are correct? 1 They read the DNA template in the 3’ to 5’ direction.2 They unwind and unzip double-stranded DNA.3 They read the terminator sequence and stop adding nucleotides to nucleic acid chains.4 They bind to the same specific sequences to start their processes. A1 and 3B2 and 3 C1 onlyD4 only2018 / H2 / ACJC PRELIM / P1 Q112The following steps describe a method to study the structure and localisation of protein kinase c in yeast cells.●tRNAs with anticodon AAG were isolated and chemically modified to carry their specific fluorescent amino acids.●During translation, chemically modified amino-acyl tRNAs bind to the large ribosomal subunit.●Fluorescent amino acids are incorporated into the elongating polypeptide chain.●After translation, the polypeptide chain folds into its native conformation and the positions of the fluorescent amino acids can be detected and studied. Which of the following describes a condition which will allow the above method to be carried out?APeptidyl transferase is specific to the fluorescent amino acid and the elongating polypeptide chain in order to catalyse the formation of a peptide bond. BSynthetic amino-acyl tRNA synthetase is specific to the fluorescent amino acid and chemically modified tRNA in order to form modified amino-acyl tRNA. CThe ribosome is specific to the mRNA sequence in order to synthesise protein kinase c.DChemically modified amino-acyl tRNA is specific to the P site of a large ribosomal subunit in order to add the fluorescent amino acid to the elongating polypeptide chain.

2018 / H2 / ACJC PRELIM / P1 Q143The table shows the genome size, number of genes and chromosome number of the following organisms:OrganismGenome size (bp)Number of genesChromosome numberE.coli bacterium4 369 0004289n = 1Baker’s yeast12 069 00062002n = 32Amoeba290 000 000 000Data not available500 – 1000 (possibly polyploidy)Rodent3 399 900 000Data not available2n = 64Humans3 200 000 00030 0002n = 46From the data provided, it is possible to conclude that1 The less complex the organism, the smaller the genome size.2 Amoeba has more non-coding DNA than humans.3 The larger the genome size, the higher the number of chromosomes.4 The number of housekeeping genes is the same for all organisms. A1 and 2 B2 and 4C3 onlyD4 only2018 / H2 / ACJC PRELIM / P1 Q134In mammalian tissues, iron enter cells via transferrin receptors (TfR) and are stored when they are bound by ferritin proteins. The synthesis of TfR and ferritin is regulated through translational controls by regulatory proteins IRP1 and IRP2, which bind to iron-responsive elements (IREs) found on mRNAs. IREs are loops found at the 5’ UTR of ferritin mRNA and 3’ UTR of TfR mRNA respectively. The effects of different iron levels on IRP1 and IRP2 are shown in the figure.

Which row correctly describes the translation