Question

After reading the paragraphs below, answer the questions that follow. Bloom syndrome is a rare disease characterized by growth deficiencies, genomic instability, and the early development of cancers. The BLM gene encodes the BLM protein, which when mutated may result in Bloom syndrome. To detect whether or not a cell has a specific region of a gene, researchers add radioactively labeled DNA molecules that can bind to their complementary DNA sequences. To detect a mutant version of the BLM gene, researchers added the radioactive DNA molecule 5' - GCTAGCTAAGCCCA - 3' to cells.

What DNA sequence were the researchers trying to detect?

3 - GCTAGCTAAGCCCA - 5'

5 - GCTAGCTAAGCCCA - 3'

5 - CGATCGATTCGGGT - 3'

3 - CGATCGATTCGGGT - 5'

Answer 1

Bloom syndrome (BS) is a rare autosomal recessive disorder characterized by growth deficiency, immunodeficiency, genomic instability, and the early development of cancers of many types. BLM, the protein encoded by BLM, the gene mutated in BS, is localized in nuclear foci and absent from BS cells. BLM encodes a DNA helicase, and proteins from three missense alleles lack displacement activity. BLM transfected into BS cells reduces the frequency of sister chromatid exchanges and restores BLM in the nucleus. Missense alleles fail to reduce the sister chromatid exchanges in transfected BS cells or restore the normal nuclear pattern. BLM complements a phenotype of a Saccharomyces cerevisiae sgs1 top3 strain, and the missense alleles do not. This work demonstrates the importance of the enzymatic activity of BLM for its function and nuclear localization pattern.

What DNA sequence were the researchers trying to detect?

Are you referring to the choices below?