Preview

Meselson and Stahl

Better Essays
Open Document
Open Document
1272 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Meselson and Stahl
Matthew Meselson and Franklin Stahl are two biologists who prove that DNA replication was semiconservative.
At the time, many strong evidences from experiments using bacterial viruses had already convinced most scientists that DNA was the molecule of heredity; however they knew little about the DNA replication process. After the dimensionally accurate model building by Watson and Crick, it was clear that the process of replication and information distribution have to use the DNA from parent cell as template to achieve an orderly flow of genetic inheritance to daughter cells. However the model of Watson and Crick still cannot fill the missing information about how DNA might accomplish replication.
Before the Meselson-Stahl experiment, many researches have been done on the problem of DNA replication by other scientists, but all of those efforts were ineffective or not directly relate to the replicate process. There were three hypotheses suggested; which are Semi-Conservative, Conservative and Dispersive. The first possibility is Conservative replication; one daughter cell receives the original DNA that was used as template, while the other daughter cell receives only newly replicated strand of DNA. The second possibility is Semiconservative replication; each daughter cell receives only one strand of DNA from the parent cell, while the complementary strand is newly replicated. The third possibility is Dispersive replication; each daughter cell receives a new double-strand that consists of distinct regions of DNA from either original or new strands interspersed throughout out the strand (Templin & Fetters 2002).

In 1956, Meselson and Stahl began to carry out an idea that Meselson had earlier had to investigate the problem by incorporating a heavy isotope into the DNA molecules of a microorganism and tracing the distribution of these atoms into progeny DNA by separating molecules of different density in a centrifuge. The plan of their landmark experiment on DNA

You May Also Find These Documents Helpful

  • Good Essays

    | Proved that DNA replicates in a semiconservative fashion, confirming Watson and Crick's hypothesis. Cultured bacteria in a medium containing heavy nitrogen (15N) and then a medium containing light…

    • 1676 Words
    • 7 Pages
    Good Essays
  • Good Essays

    Wgu Biochemistry Task 1

    • 801 Words
    • 4 Pages

    DNA and RNA Replication Deborah J Brooks Biochemistry (GRT1) Task 1 Western Governors University Objectives DNA Replication at Biochemical Level  Role of Ligase  Role of mRNA  Role of RNA Polymerase Inhibition related to the death cap mushroom  Introduction Nucleic acids are required for the storage and expression of genetic information. There are two chemically distinct types of nucleic acids.  DNA (deoxyribonucleic acid). The repository of genetic information.…

    • 801 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    Pt1420 Final Exam

    • 3892 Words
    • 16 Pages

    DNA replication is semiconservative, meaning that each daughter duplex consists of 1 parental strand and 1 newly synthesized daughter strand…

    • 3892 Words
    • 16 Pages
    Powerful Essays
  • Better Essays

    Wgu Biochemistry Task 1

    • 772 Words
    • 4 Pages

    Wolfe, George. (March 16, 2000a). Events at the replication fork: the lagging strand. Thinkwell Biology: Molecular…

    • 772 Words
    • 4 Pages
    Better Essays
  • Good Essays

    Radioisotopic labels would be used in experiments to identify semi-conservative replication in prokaryotes. Because we anticipated that a labeled DNA would have different density with unlabeled, which means, by analyzing the different density of DNAs, we can determine which of DNA is labeled, half-labeled or unlabeled. To this end, I will use c13 label the bacteria and abruptly change carbon source with C12. Then I will collect four samples in different time and analyze the results from centrifugal by ultraviolet absorption.…

    • 585 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Week 5 Dna Worksheet

    • 577 Words
    • 3 Pages

    * There has been a major effort in the history of science to figure out the structure of DNA. Having a double standard helix DNA has a uniform a diameter in its entire length. The helixes fit within a defined three dimensional space because they are both right handed. Polynucleotide chains are held together by the bases in the (center) hydrogen bonding with the bases on the opposite polynucleotide. Two polynucleotides are form around the outside of the helix with the bases extending into the center. Known as complementary base pairing; hydrogen bonding is a very specific process. Scientist had identified all the atoms and knew how they were bound together. What was not understood was the capacity to store genetic information, copy it and pass it from generation to generation, and the specific three dimensional arrangements of atoms that gave DNA its unique proprieties.…

    • 577 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    5. Given the state of knowledge at the time of Avery, Macleod, and McCarty experiment, why was it difficult for some scientists to accept that DNA is the carrier of genetic information?…

    • 1144 Words
    • 5 Pages
    Powerful Essays
  • Good Essays

    Biology 101 final review

    • 1097 Words
    • 8 Pages

    Watson and Crick reported that DNA consisted of two polynucleotide strands wrapped into a double helix.…

    • 1097 Words
    • 8 Pages
    Good Essays
  • Good Essays

    a wet one Pauling wanted gis model to be the first accurate model of DNA so he printed it quickly. Another scientist named Rosalind Franklin looked at a wet sample of DNA and realized it had two strands. Watson and crick Two students from Cambridge University looked at Pauling's paper and recognized it. They had made a similar model with a triple helix and knew Pauling was wrong,Watson and Crick looked over Franklin's work and made a new model with a double helix.…

    • 679 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    01.05 biology

    • 363 Words
    • 4 Pages

    -Self-replicating molecules are essential to the most popular hypotheses about the origin of life on Earth because these molecules can explain how one organism has a similar genetic code of a different organism, which wouldn’t be possible without the molecules.…

    • 363 Words
    • 4 Pages
    Satisfactory Essays
  • Good Essays

    Biology Final Review

    • 17056 Words
    • 69 Pages

    BSC2011C Final Review Unit 1 Review Ch. 25, 22, 23, 24, 26, 19, 27 Ch. 25 1. Life is metabolism and heredity. Metabolism is the mechanism that creates order and complexity from chaos, by acquiring and expending energy. Heredity is the ability of an organism to copy itself and it is broken down into: i. Multiplication, ii. Inheritance, iii. Variation. 2. DNA codes via RNA for 20 of naturally occurring amino acids. Amino Acids are the building blocks of proteins and bodies. DNA stores and transmits hereditary information, but proteins do most of the work. DNA IS THE UNIVERSAL DIGITAL CODE FOR LIFE. To replicate and synthesize proteins, DNA relies on the pre-existence of protein molecules and RNA molecules. 3. RNA is the bridge between DNA and proteins, via mRNA for transcription and rRNA for translation. Thus, RNA can survive on its own while DNA relies on the existence of RNA and proteins, with them DNA is helpless. 4. The 4 points of “first life” are: 1. The Abiotic (non-living) synthesis of small organic molecules, such as amino acids and nucleotides. 2. The joining of these small molecules into macromolecules, including proteins and nucleic acids. 3. The packing of these molecules into “protobionts,” droplets with membranes hat maintained an internal chemistry different from that of their surroundings. 4. The origin of self-replicating molecules that eventually made inheritance possible. 5. The first cells to develop occurred in this order: Monomers > Polymers > Protobionts > RNA ‘world’ > DNA protobionts > first cell. 6. Fossils are the evidence of life and evolution. Organisms trapped in sediment > remain mineralized with hard and soft parts. 7. Fossils can be dated by two methods: Radiometric dating & Magnetism. In Radiometric dating, the age is based on the decay of radioactive isotopes. A radioactive “parent” isotope decays to a “daughter” isotope at a constant rate. The rate of decay is expressed by the half-life, the time requires for 50% of the parent…

    • 17056 Words
    • 69 Pages
    Good Essays
  • Powerful Essays

    Franklin, s. (2003, April 24). BBC News. Retrieved from My aunt, the DNA pioneer: http://www.physics.org/explorelink.asp?id=3131&q=DNA&currentpage=1&age=0&knowledge=0&item=3…

    • 3692 Words
    • 15 Pages
    Powerful Essays
  • Better Essays

    biochemistry Task 1

    • 793 Words
    • 3 Pages

    DNA replication is a process by which two DNA molecules are formed from one DNA molecule. In simple words, it’s like ‘duplication’ of a DNA molecule. The DNA molecule is copied whereby each of the new molecules contains a single strand of the original ‘parental’ DNA and one of the newly formed DNA strand (Weaver, 2005). The process occurs in a series that contains four steps; Initiation, Elongation, Termination and Proofreading/Correction.…

    • 793 Words
    • 3 Pages
    Better Essays
  • Good Essays

    Violinist Thumb

    • 490 Words
    • 2 Pages

    Studying DNA can be extremely tedious and overwhelming. When Francis Crick and James Watson introduced the double helix, it was easy, for scientist, to comprehend the system, but it was rather difficult to understand how the DNA genes made proteins, which is the vital part. To fully grasp this concept scientist had to not only examine DNA, but they had to study RNA as well. The dispute, however, with DNA is that it actually is an elaborate and intricate code where these codes conceal its instructions.…

    • 490 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Study Guide on Genes

    • 1568 Words
    • 7 Pages

    • James Watson and Francis Crick were the first to solve the structure (structure=function) of DNA.…

    • 1568 Words
    • 7 Pages
    Good Essays