Bio 311C Week 9 QUESTIONS AND ANSWERS A+ GRADED
Essential Properties of a Molecule of Heredity
- Sufficient variability to store information.
- Able to make copies of information.
- Information should be accessible for gene expression.
T.H. Morton
Discovered that chromosomes are made of DNA, proteins, and genes.
1928, Fredrick Griffith
Discovered the there was a change in genotype and phenotype due to assimilation of
foreign DNA.
1944, Avery, McCarty, and MacLeod
Discovered that transformation is due to DNA
- Purified S cells, only leaving proteins, DNA, etc (candidates for which might be
responsible for transformation)
1952, Hershey and Chase
Discovered that DNA, not protein, makes genetic material.
- Used bacteriophage to infect bacteria and the DNA of the T2 bacteriophage is what
infected the bacteria.
1950, Erwin Chargaff
Chargaff's Rules
- The base compositions of DNA varies between species.
- In all species, the number of A-T bases and G-C bases are equal.
%A = %T and %G = %C, #of purines = # of pyrimidines
Rosalind Franklin
DNA is a double helix.
- Used X-Ray crystallography images to see that purine and pyrimidine diameter's were
constant.
Watson and Crick
- The two complementary strands of DNA run anti-parallel to one another.
- Proved the semiconservative theory.
Semiconservative Model
The parental DNA is split and one strand goes to each daughter strand. An additional
new strand is synthesized in the daughters helixes. The daughter DNA then splits, one
of the helixes receiving an old strand from the original parent strand and and
synthesizing a new strand and the other helix consisting of two new strands.
Conservative Model
The parental DNA is completely replicated by one of its daughter helixes, and then that
daughter helix is completely replicated by the next generation.
Dispersive Model
Each strand of both daughter molecules contains a mixture of old and newly
synthesized DNA.
Purine
Essential Properties of a Molecule of Heredity
- Sufficient variability to store information.
- Able to make copies of information.
- Information should be accessible for gene expression.
T.H. Morton
Discovered that chromosomes are made of DNA, proteins, and genes.
1928, Fredrick Griffith
Discovered the there was a change in genotype and phenotype due to assimilation of
foreign DNA.
1944, Avery, McCarty, and MacLeod
Discovered that transformation is due to DNA
- Purified S cells, only leaving proteins, DNA, etc (candidates for which might be
responsible for transformation)
1952, Hershey and Chase
Discovered that DNA, not protein, makes genetic material.
- Used bacteriophage to infect bacteria and the DNA of the T2 bacteriophage is what
infected the bacteria.
1950, Erwin Chargaff
Chargaff's Rules
- The base compositions of DNA varies between species.
- In all species, the number of A-T bases and G-C bases are equal.
%A = %T and %G = %C, #of purines = # of pyrimidines
Rosalind Franklin
DNA is a double helix.
- Used X-Ray crystallography images to see that purine and pyrimidine diameter's were
constant.
Watson and Crick
- The two complementary strands of DNA run anti-parallel to one another.
- Proved the semiconservative theory.
Semiconservative Model
The parental DNA is split and one strand goes to each daughter strand. An additional
new strand is synthesized in the daughters helixes. The daughter DNA then splits, one
of the helixes receiving an old strand from the original parent strand and and
synthesizing a new strand and the other helix consisting of two new strands.
Conservative Model
The parental DNA is completely replicated by one of its daughter helixes, and then that
daughter helix is completely replicated by the next generation.
Dispersive Model
Each strand of both daughter molecules contains a mixture of old and newly
synthesized DNA.
Purine
