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.
The final proof for DNA as the genetic material come from the experiments of
1. Griffith
2. Hershey and chase
3. Avery, Macleod and McCarty
4. Hargobind Khorana
Transformation was discovered by
(1) Meselson and Stahl
(2) Hershey and Chase
(3) Griffith
(4) Watson and Crick
The beginning of understanding genetic transformation in bacteria was made by
(1) Frederick Griffith
(2) Hershey and Chase
(3) Watson and Crick
(4) TH Morgan
Role of DNA in heredity was discovered for the first time through experiments involving
(1)Transformation using E.coli
(2)Transduction involving bacteriophage
(3)The use of enzymes protease and nuclease
(4)Transformation using heat killed virulent and living non virulent S.pneumoniae
Which of the following statements is correct?
I. The biochemical nature of genetic material was not defined from the experiments conducted by Griffith
II. Working on transformation Avery et al concluded DNA is genetic material but not all biologists were convinced
III. RNA is the genetic material in TMV, QB bacteriophage etc.
IV. DNA is the predominant genetic material while RNA performs dynamic functions of messenger adapter
V. Viruses having DNA genome and having shorter life span mutate and evolve faster
(1) All are correct
(2) I and II
(3) All except V
(4) III and IV
Frederick Griffith discovered:
(1) DNA is the genetic material
(2) RNA can be the genetic material
(3) Sterptococcus has two strains
(4) Bacterial transformation
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
1. | It protects the bacterium from desiccation |
2. | It provides means of locomotion |
3. | It allows the bacterium to "hide" from the host's immune system. |
4. | It allows the bacterium to attach to the surface |