The fruit fly Drosophila melanogaster has about 2 x 10^8 base pairs of DNA per haploid genome, of which about 75% in nonrepeated DNA. The DNA is distributed among four pairs of homologous chromosomes, which have a total of about 5,000 visible bands when in polytene forms in the salivary gland. The number of genes initially estimated from mutational studies was also about 5,000 but recent DNA sequencing studies suggest that the gene number may be somewhat higher. a. Why was it tempting to speculate that each band corresponds to a single gene? What does this suggest about the number of different proteins Drosophila can make? Does that seem like a reasonable number to you? b. Assuming all the nonrepeated DNA is uniformly distributed in the chromosomes, how much nonrepeated DNA (in base pairs) is there in average band?

The fruit fly Drosophila melanogaster has about 2 x 10^8 base pairs of DNA per haploid genome, of which about 75% in nonrepeated DNA. The DNA is distributed among four pairs of homologous chromosomes, which have a total of about 5,000 visible bands when in polytene forms in the salivary gland. The number of genes initially estimated from mutational studies was also about 5,000 but recent DNA sequencing studies suggest that the gene number may be somewhat higher. a. Why was it tempting to speculate that each band corresponds to a single gene? What does this suggest about the number of different proteins Drosophila can make? Does that seem like a reasonable number to you? b. Assuming all the nonrepeated DNA is uniformly distributed in the chromosomes, how much nonrepeated DNA (in base pairs) is there in average band?

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Description: The fruit fly Drosophila melanogaster has about 2 x 10^8 base pairs of DNA per haploid genome, of which about 75% in nonrepeated DNA. The DNAis distributed among four pairs of homologous chromosomes, which have a total of about 5,000 visible bands w

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter11: Genome Alterations: Mutation And Epigenetics

Section: Chapter Questions

Problem 16QP: Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior...

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