HED4812 Assignment 5 (QUESTIONS AND COMPLETE ANSWERS) |graded A+

HED4812 Assignment 5 (QUESTIONS AND COMPLETE ANSWERS) 2024 - DUE 30 DECEMBER 2024 What are the products of semiconservative replication for a double-stranded DNA molecule? - Answer Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand. Why is DNA replication essential for a cell? - Answer An organism must copy its DNA to pass genetic information to its offspring. What is the function of the parental DNA in replication? - Answer It serves as the template for DNA replication. Which enzyme breaks the hydrogen bonds during replication? Replication fork Stabilizing proteins DNA helicase ATP - Answer DNA Helicase How do stabilizing proteins work on the DNA? They bind to the single-stranded DNA. They bind to the double-stranded DNA. They form the replication fork. They use ATP to break the hydrogen bonds - Answer They bind to single-stranded DNA. In which direction does the replication fork move? - Answer It moves ahead of the newly synthesized DNA. What ensures that the single strands of DNA do not come back together? ATP DNA helicase Stabilizing proteins The replication fork - Answer Stabilizing proteins What characteristic of DNA allows two connected DNA polymerases to synthesize both the leading and lagging strands? DNA is flexible. DNA is double-stranded. DNA has a helical shape. DNA is antiparallel. - Answer DNA is flexible What is the function of connector proteins? - Answer They link the leading strand DNA polymerase and the lagging strand DNA polymerase together. Which DNA strand is synthesized continuously? Lagging strand Neither the leading nor the lagging strand is synthesized continuously. The leading and lagging strands are both synthesized continuously. Leading strand - Answer Leading strand. Which of the following are terms associated with Okazaki fragments? Discontinuous DNA ligase Lagging strand Lagging strand, DNA ligase, and discontinuous - Answer Lagging strand, DNA ligase, and discontinuous Why is the DNA synthesis of the lagging strand considered discontinuous? - Answer The synthesis is moving in the opposite direction from the replication fork. Stages in which the lagging strand is synthesized: - Answer 1. DNA polymerase begins synthesizing the lagging strand by adding nucleotides to a short segment of RNA. 2. After each strand of the lagging strand is complete, it is released from the DNA polymerase. 3. A different DNA polymerase replaces the RNA segments with DNA. 4. DNA ligase seals the gaps between the pieces, and eventually forms a continuous strand. In DNA replication, which nucleotides would pair up with the following nucleotides? A C G - Answer A ---- T C ---- G G ---- C Which of the following build(s) new strands of DNA? The origins of replication DNA polymerases The lagging strand The leading strand Parental DNA - Answer DNA polymerase Correct; DNA polymerases build new strands of DNA by adding DNA nucleotides one at a time. Which statement about DNA replication is CORRECT? DNA ligase helps assemble the leading strand. The lagging strand is one of the strands of parental DNA. The leading strand is one of the strands of parental DNA. The lagging strand is built continuously. The leading strand is built continuously, and the lagging strand is built in pieces. - Answer The leading strand is build continuously, and the lagging strand is built in pieces. During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA? T A C G U - Answer T The molecule that seals the gaps between the pieces of DNA in the lagging strand is RNA. the leading strand. DNA ligase. DNA polymerase. the replication fork. - Answer DNA ligase Which statement about DNA replication is FALSE? DNA ligase adds nucleotides to the lagging strand. The two strands of parental DNA are separated during DNA replication. DNA polymerase builds a new strand by adding DNA nucleotides one at a time. Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways. The lagging strand is made of a series of pieces that must be joined together to make a continuous strand. - Answer DNA ligase adds nucleotides to the lagging strand. What was the significance of Frederick Griffith's experiments with Streptococcus pneumoniae? - Answer He showed that the DNA from strain S cells could transform strain R cells. For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic material was proteins, and not DNA. The reason for this belief was that proteins are more complex than DNA. What was the basis of this thinking? - Answer Proteins have a greater variety of three-dimensional forms than does DNA. Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine? - Answer 12% Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that - Answer the amount of A is always equivalent to T, and C to G. Which of the following can be determined directly from X-ray diffraction photographs of Crystallized DNA? the rate of replication the frequency of A vs. T nucleotides the bond angles of the subunits the sequence of nucleotides the diameter of the helix - Answer the diameter of the helix What kind of chemical bond is found between paired bases of the DNA double helix? hydrogen covalent phosphate ionic sulfhydryl - Answer hydrogen It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following? side groups of nitrogenous bases