Hershey and Chase Experiment

Q.

(a) Why did Hershey and Chase use radioactive P32 and S35 in their experiments? Explain.

(b) Following the experiments conducted by them, write what conclusion did they arrive at and how. [5 marks]

Q. The experimental proof for semiconservative replication of DNA was first shown in a

1. Plant
2. Bacterium
3. Fungus
4. Virus

Q. Hershey and Chase used radioactive phosphorus to label the ______ core and radioactive sulphur to label the ______ coat of the bacteriophage.

1. RNA, protein
2. protein, RNA
3. protein, DNA
4. DNA, protein

Q. Taylor conducted experiments on ___________ to prove the semiconservative nature of DNA replication.

1. Pisum sativum
2. Vicia faba
3. bacteriophage
4. E.coli

Q. The elements used in Hershey and Chase’s experiments were:

1. ${}^{32}Pand{}^{35}S$
2. ${}^{36}Pand{}^{38}S$
3. ${}^{45}Pand{}^{48}S$
4. ${}^{24}Pand{}^{27}S$

Q.

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

Q.

Which of the following statements is true about the Hershey-Chase experiment?

1. R-strain contain phosphorus and thus can be labelled with radioacting phosphorus.

2. DNA contain sulphur and can be labelled with ${}^{35}S$

3. Most of radioactivity was found associated with cells inferted by bacteriophage having radioactive sulphur.

4. Most or radioactivity was found associated with cell infeted by bacteriophage having radioctive phosphorus.

Q.

Why are gram-negative bacteria usually pathogens?

Q.

Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a triplet?

1. Nirenberg and Matthaei

2. Hershey and Chase

3. Beadle and Tatum

4. Morgan and Sturtevant

Q.

Which of the following observations helped Hershey and Chase confirm that DNA is the genetic material?

1. Phage particles grown in a medium containing radioactive phosphorus could transmit radioactivity to the daughter phage particles.

2. R strain of pneumococcal bacteria gets transformed into S strain.

3. The sample to which DNAse was added could not transform.

4. DNA has a double helical structure.

Q. State whether true or false:

Hershey and Chase observed after centrifugation of the radiolabelled culture media that, most of the phosphorus was found in the pellet, while sulphur was found in the supernatant.

1. True
2. False

Q. Which amongst the following scientists was successful in discovering that the genetic code is a “triplet”?

1. Meselson and Stahl
2. Marshall Nirenberg
3. Hershey and Chase
4. Morgan and Sturtevant

Q.

Explain the role of radioactive isotopes in the field of medicine.

Q. Jacob and Monad won Nobel Prize for their work on:

1. Operon model
2. Structure of gene
3. Genetic diseases
4. Function of gene

Q. Hershey and Chase used radioactive phosphorus to label the ______ core and radioactive sulphur to label the ______ coat of the bacteriophage.

1. DNA, protein
2. protein, DNA
3. protein, RNA
4. RNA, protein

Q. Experimental material used by Hershey and Chase for proving that DNA controls heredity was

1. Diplococcus pneumoniae
2. Salmonella typhimurium
3. T2 phage
4. TMV

Q.

What is the weight of virus?

Q.

Is phage latin or greek?

Q.

What kind of bacteriophages carry out specialized transduction?

Q. pBR322 is a:

1. Radioactive isotope of P
2. Artificial plasmid, used as a vector for cloning gene in E.coli
3. Radioactive bromine used as a genetic marker for the study of metabolic pathway
4. A variety of maize

Q.

Did Hershey and Chases experiment demonstrate that DNA was a double helix?

Q. Whose experiments cracked DNA and discovered the triplet nature of genetic code?

1. Hershey and Chase
   
2. Nirenberg and Matthaei
   
3. Beadle and Tatum
   
4. Morgan and Sturtevant
   

Q. For replication of prokaryotic vector in a host cell, the vector needs

1. foreign DNA
2. cloning site
3. selectable marker
4. ori

Q. A bacteriophage is a type of

1. Bacteria that attack viruses
2. Fungus that attacks bacteria
3. Protozoan
4. Virus that infects bacteria

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

Q. The experimental proof for semiconservative replication of DNA was first shown in a

1. Plant
2. Bacterium
3. Fungus
4. Virus

Q. The plasmid derived from E. Coli plasmid Col EI is?

1. YIP
2. pYAC
3. pBR-$322$
4. Ti-plasmid

Q. Hershey and Chase experimented with radioactively labeled phosphorus and sulphur to determine that DNA and not protein is the genetic material. Which of the following was essential to this confirming experiment?

1. Sulphur is present in amino acids in the protein coat of bacteria
2. Phosphorus is present in high amounts in DNA
3. Phosphorus is not present in amino acids in the protein coat of bacteria
4. All of the above were critical to demonstrating DNA is involved in the genetic material

Q. In Hershey and Chase experiments, radioactive P${}^{32}$ was used to culture bacteriophages which resulted in radioactive?

1. Viral DNA
2. Bacterial capsule
3. Viral proteins
4. Plasma membrane of bacteria

Q.

When bacterial genes are transferred to another bacterium by a virus it is called?