BIO 201 Homework 10 | Questions with 100% Correct Answers

BIO 201 Homework 10 | Questions with 100% Correct Answers When replication starts, an origin of replication forms, consisting of two __ moving in opposite directions replication forks DNA double helix is separated into single strands by the enzyme DNA helicase Newly-exposed, unreplicated DNA is protected by single-strand binding protein Short segments of RNA are synthesized, called RNA primers The enzyme that synthesizes the short segments of RNA is called a Primase The short RNA segments provide a free ___ for replication 3' OH New DNA is synthesized in the ____ direction 5' to 3' The enzyme that removes tightened coils ahead of the replication fork is Topoisomerase The enzyme that catalyzes new DNA synthesis is DNA polymerase DNA synthesis occurs continuously on the leading strand DNA synthesis occurs in small sections on the lagging strand Fragments of discontinuous DNA synthesis are called Okazaki fragments Gaps in the sugar-phosphate backbone of DNA are closed by DNA ligase Eukaryotic cells store their DNA in the form of linear chromosomes. This creates problems for replication of DNA at the ends of the chromosomes because DNA polymerase can only synthesize DNA in the 5' to 3' direction. Suppose actively dividing eukaryotic cells were treated with a chemical that blocks the activity of the enzyme telomerase. What would happen to these cells? Cells would lose DNA at the ends of the chromosomes over many generations The genetic material in bacteria is double-stranded DNA DNA replication in bacteria begins at a single origin and proceeds in both directions. DNA replication is said to be semi-conservative How is bacterial DNA replication different from eukaryotic DNA replication? Bacterial DNA replication takes place from a single origin of replication, while eukaryotes have multiple origins of replication. Which of the following prevents supercoiling of the DNA strands ahead of the replication bubble? Topoisomerase A child has a disease that is causing severe growth delays and rapid aging. His cells are assayed, and it is noticed that there is a severe decrease in DNA synthesis compared to normal cells. When DNA from his cells was gently heated to separate the double helix, numerous, small, single-stranded fragments of about 1000 base pairs were found. Which enzyme is likely to be defective in this child? ligase Which of the following synthesizes the daughter strands during DNA replication? DNA polymerase Arrange the following proteins in the proper order in which they participate in DNA replication. 1 = Primase 2 = Helicase 3 = Single-strand binding proteins 4 = DNA polymerase I 2, 3, 1, 4 RNA primers are removed by the action of the enzyme DNA pol I. The enzyme that unwinds a segment of the DNA molecule is Helicase Before the lagging strand can begin assembling new DNA nucleotides, which of the following must occur? RNA primase constructs a short RNA primer How do DNA polymerase I and DNA Polymerase III differ? DNA Polymerase III synthesizes the majority of the DNA, while DNA Polymerase I synthesizes DNA in the regions where the RNA primers were laid down on the lagging strand DNA polymerases cannot replicate the 3' end of linear chromosomes Which of the following best describes the function of telomerase at the telomere? It adds new DNA to the longer strand of the telomere overhang. Evaluate the statements below and determine which is the best explanation for why bacteria don't use telomerase. Bacteria have circular chromosomes that do not shorten. The molecule that carries information from the DNA specifying a polypeptide to ribosomes Mrna The synthesis of an RNA copy of a gene. Transcription The synthesis of a specific sequence of amino acids on a ribosome. Translation A molecule found in the nucleus of cell that contains the cell's genome. DNA A molecule made of amino acids that correspond to the genetic information in a structural gene. Polypeptide During the process of transcription in a eukaryote RNA polymerase synthesizes new nucleotide chains in the 5' to 3' direction. During the process of translation in a eukaryote mRNA interacts with ribosomes in the cytoplasm. In transcription, the goal is synthesis of