Hershey-Chase Experiment — NEET Biology
📚 Practice ConceptRadioactive phages were allowed to attach to E. coli bacteria. Then, as the infection proceeded, the viral coats were removed from the bacteria by agitating them in a blender. The virus particles were separated from the bacteria by spinning them in a centrifuge.
Arrange the following key steps of Hershey and Chase’s experiment in the correct chronological sequence: 1. Radioactive phages were allowed to infect E. coli bacteria. 2. Some viruses were grown in medium containing radioactive sulfur (³⁵S) → labeled proteins. 3. Some viruses were grown in medium containing radioactive phosphorus (³²P) → labeled DNA. 4. After infection, phage coats were removed by blending and separated by centrifugation. 5. Bacteria infected with ³²P-labeled phages became radioactive, showing DNA entered cells.
View solution & NCERT explanation
Correct answer: B — 3 → 2 → 1 → 4 → 5
First, bacteriophages were labeled in two ways: with ³²P for DNA and with ³⁵S for protein. Then both types infected E. coli. Blending and centrifugation separated viral coats from bacteria. Radioactivity was detected only inside bacteria infected with ³²P-labeled DNA, proving DNA is the genetic material.
What does NCERT say about Radioactive phages were allowed?
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Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.