Home
Class 12
BIOLOGY
a) Write the conclusin drawn by Griffith...

a) Write the conclusin drawn by Griffith at the end of his experiment with Streptococcus pneumoniae.
b) How did O.Avery, C.MacLeod and M. McCarty prove that DNA was the genetic material? Explain.

Text Solution

Verified by Experts

He concluded that the R strain bacteria had somehow been transformed by the heat killed S strain bacteria. Heat killed S strain enabled the R strain to synthesis a smooth polysaccharide coat and become virulent.
Promotional Banner

Topper's Solved these Questions

  • XII BOARDS

    XII BOARD PREVIOUS YEAR PAPER ENGLISH|Exercise SECTION-E|6 Videos

  • XII BOARDS

    XII BOARD PREVIOUS YEAR PAPER ENGLISH|Exercise [OUTSIDE DELHI : SET-II] SECTION -A|2 Videos

  • XII BOARDS

    XII BOARD PREVIOUS YEAR PAPER ENGLISH|Exercise OUTSIDE DELHI SET III|8 Videos

  • SAMPLE PAPER 2019

    XII BOARD PREVIOUS YEAR PAPER ENGLISH|Exercise Section E Part B|3 Videos

Similar Questions

Explore conceptually related problems

How did Hershey and Chase proved that DNA is the hereditary material? Explain their experiment with suitable diagram.

How did Hershey and Chase differentiate between DNA and protein in their experiment while proving that DNA is the genetic material?

What is meant by R-cells and S-cells with which Frederick Griffith carried out his experiments on Diplococcus pneumoniae? What did he prove from these experiments?

Define transformation in Griffith's experiment. Discuss how it helps in the identification of DNA as the genetic material.

Recell the experiments done by frederick Griffith, Avery, MacLeod and McCarty, where DNA was speculated to be the genatic material. If RNA , instead of DNA was the genetic meterial, would the heat killed strain of pneumoccus have transformed the R-strain into virulent strani? Explain.

(a) Describe the series of experiments of F. Griffith. Comment on the significance of the results obtained. (b) State the contribution of Macleod, McCarty and Avery.

(a) Describe the series of experiments of F. Griffith. Comment on the significance of the results obtained. (b) State the contribution of Macleod, McCarty and Avery.

Explain the experiment performed be Griffith on Streptococcus pneumonia. What did he conclude from this experiment? Name the three scientists who followed up Griffith's experiments. What did they conclude and how?

Answer the following questions based on Meselson and Stahl's experiment of E. coli : (a) Write the name of the chemical substance used as the only source of nitrogen in the experiment. (b) Why did they allow the synthesis of the light and the heavy DNA molecules in the organism ? (c ) How did they distinguish the heavy DNA molecules from the light DNA molecules? Explain. (d) Write the conclusion the scientists arrived at, at the end of the experiment.

Answer the following questions based on Meselson and Stahl s experiment: (a) Write the name of the chemical substance used as a source of nitrogen in the experiment by them. (b) Why did the scientists synthesise the light and the heavy DNA molecules In the organism used in the experiment ? (c) How did the scientists make it possible to distinguish the heavy DNA molecule from the light DNA molecule ? Explain. ((1) Write the conclusion the scientists arrived at after completing the experiment.

XII BOARD PREVIOUS YEAR PAPER ENGLISH-XII BOARDS-COMPTT
  1. A colour blind boy is born to a couple with a normal colour vision. Wr...

    Text Solution

    |

  2. Mention any two conditons that enhance the chances of syngamy in organ...

    Text Solution

    |

  3. a) Write the conclusin drawn by Griffith at the end of his experiment ...

    Text Solution

    |

  4. Plants like potato, sugarcane do not require seeds for producing new p...

    Text Solution

    |

  5. Explain the role played by predators in a community.

    Text Solution

    |

  6. Name the first antibiotic discovered and by whom.

    Text Solution

    |

  7. What happens when chromatids fail to segregate during cell division cy...

    Text Solution

    |

  8. ABO blood groups is a good example of co-dominance. Justify.

    Text Solution

    |

  9. What is the pathogenic property of baculovirus, used as a biological a...

    Text Solution

    |

  10. (a) What is an "allergic reaction"? (b) Name any two drugs used to q...

    Text Solution

    |

  11. List any two types of IUDs that are available for human females and st...

    Text Solution

    |

  12. Mention the rule of (i) selectable marker, (ii) Ori and (iii) rop in E...

    Text Solution

    |

  13. Write the aim with which animal breeding programmes are carried. Descr...

    Text Solution

    |

  14. (a) Draw a diagram of sectional view of human ovary and label (i) Prim...

    Text Solution

    |

  15. (a) Draw a diagram of Pistil showing pollen tube growth in angiosperm...

    Text Solution

    |

  16. What was the challenge for production of insulin using rDNA techniques...

    Text Solution

    |

  17. Name the organism from which the 'cry' genes are isolated. Mention wit...

    Text Solution

    |

  18. Excessive and continous use of pesticides has resulted in evolution of...

    Text Solution

    |

  19. Explain with the help of two examples how certain plants have evolved ...

    Text Solution

    |

  20. What type of organs eye of an Octopus and that of a human called? Give...

    Text Solution

    |