Chapter Eleven: Nucleic Acid Structure, DNA Replication, and Chromosome Structure Flashcards
Genetic Material needs to: (4)
- Contain info to build and run an entire organism
- Be copied accurately
- Be transmitted from parent to offspring
- Account for known variation between species
Most scientists believed Genetic Material would be _____________ since they are known to be much more variable than Nucleic Acid
Proteins
Who set the stage for showing what the Genetic Material would be?
Griffith
Griffith worked with two strains of the bacteria Streptococcus Pneumoniae. What two strains?
S and R strain
What strain of Streptococcus Pneumoniae is virulent and kills mice by a pneumonia infection?
S strain
What strain of Streptococcus Pneumoniae is not virulent and a mouse’s immune system would kill it?
R strain
Griffith first injected mice with the ______ strain and saw that the mice died
S
After the death of the mouse when the S strain was injected, live ______ bacteria was found which established the virulence of the S strain
S
Griffith injected the mice with the _____ Strain and saw that mice did not die. This established the non-virulence of the R strain
R
Griffith killed the virulent S strain and injected the dead S strain. Since the bacteria was killed, did the mice die?
The mice did not die
Griffith mixed the live R strain (which did not kill mice) with the heat-killed S strain (which did not kill mice) and he injected that. Live S strain was recovered, did the mice die?
The mice died
Something from the S strain was transferred to the live R strain, transforming it to the live ____ Strain
S
Whatever agent had transformed the R strain to the S strain must be the…
Genetic Material
Who took the live R Streptococcus Pneumoniae bacteria and mixed it with heat killed S strain like Griffith but they firstly treated it with enzymes to destroy a class of organic molecules
Oswald Avery
If the _______ in the heat-killed S strain were proteins, they should have been destroyed and not able to transform the live R strain into the S strain
Genes
Genes could not be…
Proteins
Genes must consist of __________ ________ since when they are destroyed, so is the ability to transform the R strain to the lethal S strain
Nucleic Acids
Who demonstrated for the first time that genes were Nucleic Acids?
Oswald Avery
Who did the second demonstration of the nature of genes?
Hershey and Chase
What type of isotopes did Hershey and Chase use in viruses?
Radioactive
Of all the organic molecules, only ______________ have Sulfur, so if they grow viruses in radioactive 35S, only Proteins will be “marked”
Proteins
Only ____________ ________ have Phosphorus so viruses grown in radioactive 32P will only mark Nucleic Acids
Nucleic Acids
Watson and Crick made the what kind of helix model?
Double
What are the three parts of Nucleic Acids?
- Pentose Sugar
- Nitrogenous Bases
- Phosphate Group
Ribose Pentose Sugar is found in….
RNA
Deoxyribose Pentose Sugar is found in….
DNA
DNA backbone is composed of alternating what two things?
Sugar and Phosphates
What are the Four Nitrogenous Bases in DNA?
A
C
G
T
What are the four Nitrogenous Bases in RNA?
A
C
G
U
What two Nitrogenous Bases are Purines?
A
G
What three Nitrogenous Bases are Pyrimidines?
C
U
T
What kind of structure does DNA have in which two strands run in opposite directions?
Antiparallel Structure
How many strands are in RNA?
One