Alfred Hershey and Martha Chase unequivocally proved that DNA is genetic material by using
1. Bacteriophage
2. Cyanophage
3. Fungi
4. Vicia faba
Fredrick Griffith accidentally discovered transformation when attempting to develop a vaccine for pneumonia. He injected mice with samples from S-strain (virulent) and/or R-strain (nonvirulent) pneumococci bacteria (Sterptococcus pneumoniae). Which of the following results is NOT consistent with Griffith's experiments?
1. injected S-strain; mouse dies.
2. injected R-strain; mouse lives.
3. injected heat-killed S-strain; mouse lives.
4. injected mixture of heat-killed S-strain and live R-strain; mouse lives.
Which scientists first gave experimental evidence that DNA is the genetic material?
1. Avery, MacLeod , and McCarty who repeated the transformation experiments of Griffith, and chemically characterized the transforming principle.
2. Garrod, who postulated that Alcaptonuria, or black urine disease, was due to a defective enzyme.
3. Beadle and Tatum, who used a mutational and biochemical analysis of the bread mold Neurospora to extablish a direct link between genes and enzymes.
4. Meselson and Stahl who showed that DNA is replicated semiconservatively.
Viruses grown on radioactive sulfur contain:
(1) Radioactive proteins but not DNA
(2) Radioactive DNA but not proteins
(3) Radioactive proteins and DNA
(4) Nonradioactive DNA and protein
By performing a series of experiments that showed the effect of R and S strains of Streptococcus pneumoniae on mice, Griffith concluded that
1. Protein digesting enzyme does not affect
transformation.
2. DNA is more stable genetic material than RNA.
3. DNA replication is semi conservative.
4. Non-virulent bacteria were tranformed by heat killed
virulent bacteria.
Transformation was discovered by:
1. Meseson and Stahl
2. Hershey and Chase
3. Griffith
4. Waston and crick
If the DNA of this virus was labeled with 32P and the protein of the virus was labeled with 35S, which molecule(s) would be present inside the cells?
(1) 35S and 32P
(2) 35S only
(3) 32P only
(4) Neither molecule would be present inside the cell
The unequivocal proof that DNA is the genetic material was provided by:
1. Avery, Macleod and McCarty
2. Hershey and Chase
3. Meselson and Stahl
4. Watson and Crick
Which scientist experimentally proved that DNA is the sole genetic material in bacteriophage?
1. Beadle and Tatum
2. Messelson and Stahl
3. Hershey and Chase
4. Jacob and Monod
Experiments by Avery, Macleod, and McCarty supported DNA as the genetic material by showing that:
(1) Both protein and DNA samples provided the transforming factor
(2) DNA was not complex enough to be the genetic material
(3) Only samples with DNA provided transforming activity
(4) Even though DNA was molecularly simple, it provided adequate variation to act as the genetic material