Biol 1610 - Class 11- Replication Pre-class Questions & Answers

Biol 1610 - Class 11- Replication Pre-class Questions & Answers You find a way to attach either a red or green fluorescent dye to nucleotides. Double-stranded DNA molecules with both strands labeled red fluoresce red, those with both strands labeled green fluoresce green, and those with one strand labeled red and the other green fluoresce yellow. You grow human cells in the presence of "red" nucleotides until both DNA strands of all chromosomes fluoresce red. You then allow one round of DNA replication in the presence of "green" nucleotides. What pattern of fluorescence do you expect to see in the sister chromatids of each chromosome? - Answer-both chromatids yellow You find a way to attach either a red or green fluorescent dye to nucleotides. Double-stranded DNA molecules with both strands labeled red fluoresce red, those with both strands labeled green fluoresce green, and those with one strand labeled red and the other green fluoresce yellow. You grow human cells in the presence of "red" nucleotides until both DNA strands of all chromosomes fluoresce red. You then allow one round of DNA replication in the presence of "green" nucleotides Continuing your experiment with "red" and "green" labeled chromosomes, you allow cells with DNA labeled "red" in both DNA strands to undergo two rounds of DNA replication in the presence of "green" nucleotides. What pattern of fluorescence would you expect to see in the sister chromatids of each chromosome? - Answer-one chromatid green, the other yellow (Read figure 12.2 before this Q) When we say that DNA replication is semiconservative, we mean that: - Answer-when DNA is replicated each new double helix contains one parental strand and one newly synthesized daughter strand. (Read the page linked above before answering this question. Also refer to figure 4.2 of your textbook and apply what you learned from module 1.) Compare the properties of the amino acid at position 257 in the wild type and the D257A mutant and determine which of these statements is TRUE. - Answer-The side chain changed from one that is acidic to one that is nonpolar. (Read the page linked above before answering this question) Using the provided data in the table as support, determine the effect of the D257A mutation? - Answer-This mutation abolished the proofreading activity of the polymerase. (Read the page linked above before answering this question.) What phenotypic impacts were NOT noticed in the D257A mutant mice? - Answer-slower replication