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DNA review

Page history last edited by PBworks 15 years, 7 months ago



DNA review







Working together using this wiki


Think of this wiki as a shared online notebook capable of producing text, audio, video, etc. Your entire group can share information using this wiki, making your research accessible to everyone. The whole is greater than the sum of its parts. Feel free to make spelling, grammar edits as you see them. Edits in RED are Mr Mason's edits for clarity.






For this activity, you will be assigned one of the review questions. After perusing the resources on the DNA resource page, provide information to answer your question. In order to get credit for your response, you must attach your username as a prefix to your submission. Your resonse should add information to the question. So, please read what has already been submitted before responding.



1.What is the contribution of each of the following scientists to our understanding of the role of nucleic acids?

a. Fredrick Griffith

mashby5: Unexpected observations while working with a bacteria called pneumococcus led to what Griffith called "transforming principle." This was the first clear linking of DNA to heredity in cells.


abranch36: He did experiments that provided additional evidence that nucleic acids are linked to heredity in cells. He also discovered the process of transformation, although his theories were not accepted until a later time.


jthayer19: Griffith proved through experements with heat killed pathogenic cells and living non pathogenic cells that DNA is the controlling genetic material in all cells.


swillis86: Griffith did an experiment suggesting that bacteria are able to transfer genetic information through transformation.


bfunck: Griffith discovered what he called the "transforming principle", which showed that genetic information could be transfered and was connected to heredity.


atruxillo: Griffith's experiment was about transformation, where in it he showed that the smooth virulent bacteria kills mice along with heat killed smooth virulent bacteria. His experiments were published in 1928 where the impact of genetics were more crucial.


thermann10: In 1928 Fred Griffith discvered transformation in bacteria. He also showed that some strains could influence the disease-causing characteristics of other strans.


mlewis412: Fredrick Griffith conducted experiments on mice and the R&S elements. He discovered tranfomation in bacteria as a result.

b. Oswald Avery

ohernandez76: He discovered that DNA is the material of which genes and chromosomes are made. His research helped determine that DNA (a nucleic acid) is the substance responsible for heredity.


ccobia: oswald avery discovered that DNA is the material of which genes and chromosomes are made.


llindsey40: He showed that DNA was the was the chemichal basis for hereditary transformations in bacteria.


wwest25: Oswald Avery showed that hereditary information is stored in DNA.


bmayer: Avery's experiments showed that neither proteins nor DNA carry genetic information. He wondered if DNA was the transforming agent. He destroyed the DNA in the first bacteria. He then saw that no hereditary information was transmitted to the second bacteria. Avery then concluded that DNA causes change to the second bacteria by transmitting traits from the first bacteria.


c. Martha Chase and Alfred Hershey

keagan6: They performed the famous experiment which demonstrated the genetic properties of protein and DNA, and were consequently able to trace DNA and protein in order to determine which is the molecule of heredity.


awilkins56: They performed the experiment by marking bacteriophages with radioactive isotypes. The results were released in a 1952 paper.


ahill425: In their experiment, Chase and Hershey were able to find which molecule of the bacteriophages were heredity by making the bacteriophages radio active. Then they were able to trace the protein and the DNA.

2. What is transformation?

hmason32: Transformation is the genetic changing of a cell occuring due to the introduction, uptake and how it is expressed of the foreign DNA in the molecular biology. First demonstrated by Oswald Avery in 1944.


awillams2:genetic alteration of a cell resulting from introduction and exposure to foreign genetic material in molecular biology.


tdonson: The cutting and pasting of DNA to create custom-made organisms containing recombiant DNA. This mainly refers to genetic engineering. Scientist making use of the natural process to engineer new organisms.


3. What is a bacteriophage?

tduke24: Bacteriophages have heads composed of protein and they are viruses that infect bacteria and sometimes destroy them by lysis, bursting, or by disintegrating the cell


pbrou: Alfred Hershey and Martha Cowles Chase were experts in Bacteriophage.


jburch41: A bacteriophage is a virus that infects bacteria. There are many different types of phage structures. They can be found insoils and intestines of animals.


ameyers73: Bacteriophage is a virus that infects bacteria. The name is commonly used in a shortened form, or "phage".


JEdwards424-Bacteriophage-parasites inside a cell that multiply in bacteria by making use of come or all of the host arganisms.


4. What was the contribution of each of the following scientist to our understanding of the structure of DNA?

a. Rosalind Franklin

zfrando- Rosalind Franklin didn't recieve a Nobel Prize because she was dead and Nobel Prizes aren't rewarded to the deceased, but Crick, Watson, and Wilkins all recieved a joint-Nobel Prize for their work on DNA.

cwolff@wc.coxmail.com - Rosalind Franklin was the first person to get a good clear cut photo of DNA.

bwhite417: Franklin made scientific contributions towards the discovery of the double helix by forming x-ray diffraction images of DNA. Her work was later used in Watson and Crick's hypothesis to prove that the double helix actually existed.


sbrou: Rosalind Franklin overcame the adversaries of being a woman in the male dominated field of biogenetics. By using her X-ray difraction images the shape of the the double helix was suggested. Her images were later found to be true when proved by Watson and Crick.


dnelson348:Franklin made it her own project to examine x-ray diffractions with DNA. She used the DNA fibers to understand the different conditions of DNA.


b. James Watson

scarson25: Watson and his partner Francis Crick found that DNA is a winding double helix.


dwaters40- (Along with Francis Crick) Found that DNA is a winding double helix where pairs of bases hold the strands together.


jsacks11: Teamed up with Francis Crick at Cambridge University and created a model of the structure of DNA.


hfurr2: Molecular biologist who worked with Fancis Crick at the physics department of the University of Cambridge. The two worked for less than a year and a half and they developed a model of the structure of DNA.


jgardner178: James Watson worked alongside Francis Crick and proposed that the structure of DNA is a double helix. After gathering information from a variety of sources they completed a model that was incorrect. More research was done and they finally developed a true model. He was awarded the 1962 Nobel Prize for Physiology or Medicine along with 2 other scientists.

c. Francis Crick

bstephens78: he discovered deoxyribonucleic acid. He "discovered" a structure for DNA. Meischer actually discoverd DNA back in 1868.


klangley15: Francis Crick worked with James Watson and used his knowledge of x-ray diffraction to help Watson uncover the structure of DNA: the double helix.


Mgottschalk5:Crick worked with W. Cochran to work out the theory of x-ray diffraction.


Cchilders32: Crick was interested in discovering how molecules make the transition from the non-living to the living and how the brain makes a conscious mind. These interests led him to the study of biophysics and thus the discovery of the DNA molecule.


d. Erwin Chargaff

Erwin figured out a pattern in DNA that in the colaboration or four bases:which are Adenine, Guanine, Cytosine, and last but not least Thymine. He noticed that there was equal amounts of Adenine and Thymine, and as well as equal amounts of Guanine and Cytosine in DNA. This was later know as A=T,and G=C, and alternatively call Chargaff’s rule.


chernandez458: He found the base-pairing rules for nucleic acids to help make a model of the structure of DNA (ex: A+G=T+C)


pcolston: Erwin chargaff discovered relationships of nucleic acids. He found out that there are as many types of DNA as there are species.


5. What is DNA replication?

tnguyen592: the act of making a duplicate copy of a double stranded DNA molecule


wreed34:when a DNA molecule seperates to produce two new molecules of the same kind.


chuffman49: It's the process when a double-stranded DNA molecule copies its self.


mhall371: It is the process of making an identical copy of a section of duplex DNA using existing DNA as a template for the synthesis of new DNA strands. It is the same in prokaryotic and eukaryotic organisms.


cedwards257:The uptake and expression of foreign DNA in a living cell that was first demostrated by Fredrick Griffith.


6. What is a mutation?

crarie: A mutation is a change in the base pairs of DNA.


igillette1: a change in the nucleotide-base sequence of a gene or DNA molecule.


tkelly137: A mutation is a permanent change in the DNA sequence of a gene.


eruiz84: A mutation is an event in which a DNA gene is damaged and alters the genetic message carried by a gene.


bleuchtman: mutation is a change to the nucleotide-base sequence of a gene or DNA molecule or RNA molecule.


7. What is meant by the "Central Dogma of DNA"?

jabrahamson8: DNA replicates its information and then codes for the production of messenger RNA during transcription. The messenger RNA then carries coded information to ribosomes which is then used for protein synthesis through translation.


ksellers30: Simply states that once information gets into protein, it can not flow back to nucleic acid.


kmcclarron: It is the framework for understanding the transfer of sequence information between sequential infomation carrying biopolymers such as DNA, RNA, and protein.


imacbeth: The "Central Dogma of DNA" simply states that DNA makes RNA and RNA in turn makes protein.


8. What is RNA?

bmccaghren1: RNA, a ribonucleic acid polymer, serves as a messenger between DNA and ribosomes. This nucleic acid is also responsible for the making of proteins out of amino acids.


JMiller1376 says: Ribonucleic acid (RNA) is a nucleic acid polymer made of nucleotide monomers,it is a messenger between DNA and ribosomes, and it is responsible for making proteins out of amino acids. RNA polynucleotides have ribose sugars and predominantly uracil unlike deoxyribonucleic acid (DNA), which contains deoxyribose and mostly thymine. RNA is made from DNA by enzymes called RNA polymerases.



9. What is transcription?

jcoats16: the process that allows a DNA squence to be enzymatically copied by an RNA polymerase so a complementary RNA can be formed.


kmitchell288: the transfer of genetic information from DNA to RNA.


apapadelias:the process where DNA is copied and transferred to RNA.


mstarke1: When the sequence information from DNA get transferred to RNA so that it can be carried to the ribosomes in the cytoplasm.


aketterling3: The process in which the genetic information from a DNA  molecule is transfered to an RNA molecule.


10. What is translation?

tmorrison76: The binding of small ribosomal subunits to a specific sequence on the mRNA chain.


asherrill7: Translation is the process of protein biosynthesis in which messenger RNA is used as a template to produce a certain protein according to the rules specified by the genetic code.


sstarta21: Translation- the process by which the mRNA code is converted to a sequence of amino acids.


hcummings: Translation is the process that converts RNA into a chain of amino acids that form a protein.

11. What is protein synthesis?

morach:Protein Synthesis is the process by which a cell builds proteins by reading the DNA from Chromosomes. In the process, the cell does a transformation and a translation.


mthompson540: When specific parts of DNA are transcribed and translated to form proteins, it is called protein synthesis.


rstinson17: Protein synthesis occurs when the cells build proteins.


kdoubek1: The process in which single amino acids are connected to each other in a order determined by a sequence in the DNA. It also involves the processes of transcription and translation.


12. What is the human genome?

nhennessee1: The Human Genome includes 24 chromosomes and is made up of 22 autosomes and X and Y.


rsmithies: It is the heredity information encoded in DNA of a human being with 23 chromosome pairs. This includes about 3 billion base pairs with more than 20,000 genes.


avinson30: The human genome is the entire set of genetic information that is embedded in 46 chromosomes found in the nucleus of each cell.





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