DNA that is transmitted to daughter cells must be accurately duplicated to maintain genetic integrity and to promote genetic continuity. In proofreading, the DNA pol reads the newly added base before adding the next one, so a correction can be made. DNA REPLICATION SOLVED MCQs with explanation (1-27) : DNA REPLICATION SOLVED MCQs with explanation (1-27) BY Dr Ichha Purak University Professor Department of Botany Ranchi Women’s College,Ranchi PowerPoint Presentation : Which of the following reactions is required for proofreading (i.e. Answer: B. Title: DNA replication 1 DNA replication. A. equal amounts of light and hybrid DNA B. all hybrid DNA C. equal amounts of light, hybrid, and heavy DNA D. twice as much light as hybrid DNA E.three times as much light as hybrid DNA The daughter cells must have the same genetic information as the parental cell So DNA replication must possess a very high degree of fidelity. Process of DNA Replication Uncoil & unzip DNA molecule Enzyme (-ase) breaks weak Hydrogen Bond between bases B. Most of the mistakes during DNA replication are promptly corrected by DNA polymerase by proofreading the base that has been just added (Figure 1). Telomeres and telomerase. Replication design challenge: proofreading. Incorrect bases are removed and replaced by the correct base, and then polymerization continues (Figure 9.13 a).Most mistakes are corrected during replication, although when this does not happen, the mismatch repair mechanism is employed. Oct 10, 2020 EGK BUCHS/2004 9 DNA Replication Replication of DNA occurs during the process of normal cell division cycles. The entire process of DNA replication can be discussed under many steps. The dynamics of this primer transfer reaction during active polymerization remain poorly understood. 3.Proofreading and repairing errors in the new strands. DNA REPLICATION MCQs DNA REPLICATION Objective Type Questions with Answers. A major function of replicative DNA polymerases is to replicate DNA with the very high accuracy. The replication of the viral genome within the infected cells is a key stage of the SARS-CoV-2 life cycle. Process of DNA Replication 3. DNA replication is the production of identical DNA helices from a single double-stranded DNA molecule. Attack by water which can lead to the removal of an amine group from the base group of a nucleotide or the loss of the entire base group. Basic Mechanisms of Replication DNA replication is semiconservative. Well outline the steps of replication and the proofreading that goes with it. 3 What well discuss DNA repair mechanisms and proofreading correct most replication errors. tive site, which prefers double-stranded DNA (for review, see Joyce and Steitz 1994). Lesson 4 - DNA replication and repair (PPT) During semi-conservative mode of replication first, unwinding of double helix takes place. Proofreading also occurs in mRNA translation for protein synthesis. ADVERTISEMENTS: These two strands are easily separable because the hydrogen bonds which hold […] Theta replication is a type of common in E. coli and other organisms possessing circular DNA Double-stranded DNA unwinds at the replication of origin Producing single-stranded templates for the synthesis of new DNA. This is a micrograph, three replication bubbles are visible along the DNA cultured Chinese hamster cells. Andy HowardIntroductory Biochemistry4 December 2008; 2 DNA replication accuracy! Repair mechanisms correct the mistakes. The first checkpoint is a result of the enzyme significant binding preference for the correct versus incorrect nucleoside triphosphate during polymerization. 11. A. DNA polymerases B. Helicases C. Single-stranded binding proteins D. Topoisomerases. Molecular structure of DNA. Why must a cell duplicate its DNA??? at least 10 of 15 template-dependent human) polymerases lack intrinsic proofreading activity (2, 3), it is possible that dissociation from DNA after misinsertion may allow proofreading by the exonuclease activity intrinsic to another replication or repair protein, such as Pol δ, Pol ϵ, or apurinic/apyrimidinic endonuclease .