Question

1) Suppose that gene A 3,000 bp. Suppose that g contained within intron 1 opposite directions for the two genes. covers 10,000 base pairs (bp) and has 2 exons; the intron in gene A is ene B covers 1,500 bp and has two exons. Gene B is completely of gene A. The direction of the transcriptional bubble moves in A. Draw the genomic organization (i.e., exons and introns) of gene A AND gene B. Label the polarity of the DNA strands and draw a transcription arrow for each gene and the direction of movement of the transcription bubble. B. Indicate the DNA template strand for transcription for each gene. C. Indicate the location of the promoter for each gene 2) mutation 3aonion The genomic organization of gene X is shown above; exons are shown as boxes. The gene is alternatively spliced, such that transcript 1 is composed of exons 1-6, while transcript 2 is composed of exons 1-5. Mutants that showed phenotypes due to defects in gene X activity (both protein activity and levels of protein) were isolated. Vertical dotted lines indicate point mutations; horizontal bars show the extent of deletion mutations. A. Indicate with an arrow the start and direction of transcription. B. Could the mutation 5 correspond to a missense mutation? Why or why not? C. Mutation 6 caused a phenotype, yet the deletion is in an intron. In ONE sentence, explain how the deletion mutation affected gene X activity D. Does mutation 3 disrupt the regulation of gene X or protein X itself? Justify your answer in ONE sentence. E. Which of the mutations could possibly correspond to a nonsense mutation? F. Which of the mutations could possibly affect an enhancer sequence? G. Which of the mutations could possibly correspond to a frameshift mutation? H. Which of the mutations could affect RNA stability? 3) You are following five independent traits in a mating of parents with the genotypes of AaBBCcDdEe x AaBbCcDdEe. Assume that all traits are independent. A. What is the probability that a progeny of the mating will be AaBbCcDDEE? B. What is the probability that a progeny of the mating will be aabbccddee? C. If you were to do a Punnett square for this cross, what would be the size of the square (i.e 2x2, 4x4, 8x16, etc.).

Answer 1

Transcription start site for Gene B Promoter region for Gene A 5' 3' 3' Promoter region for Gene B Transcription start site for Gene A Red boxes Exons in Gene A Green boxes Exons in Gene B Black boxes Introns

Transcription start site mutation mutation TAA ATG exon 1 exon 2 exon 3 enon 4 mutation 2 mutation 6 Mutation 5 is in the intron. It does not code for amino acid. Hence it can not be missense mutation Mutation 6 might have altered the splicing efficiency of the mRNA leading to the synthesis of abnormal protein.