Hershey chase experiment was done on:
First, the core concept here is the Hershey-Chase experiment. I remember that this experiment was crucial in proving that DNA, not protein, is the genetic material. They used bacteriophages, which are viruses that infect bacteria. The experiment involved labeling the protein coat with sulfur-35 and the DNA with phosphorus-32. When the phages infected the bacteria, only the DNA entered the bacterial cells, showing that DNA is the hereditary material.
So the correct answer should be bacteriophage. The options likely included bacteria, viruses, or other organisms. Let's assume the options are A. Bacteria, B. Bacteriophage, C. Yeast, D. Algae. The correct answer would then be B.
For the wrong options: Option A is incorrect because the experiment was about phages infecting bacteria, not the bacteria themselves. Option C and D are not relevant here.
The clinical pearl here is that the Hershey-Chase experiment is a classic example in molecular biology, key for understanding DNA's role. Students should remember the use of radioactive isotopes to differentiate between DNA and protein.
Putting it all together, the correct answer is B. Bacteriophage.
**Core Concept**
The Hershey-Chase experiment demonstrated that DNA, not protein, is the genetic material in bacteriophages. This foundational experiment in molecular biology used radioactive labeling to track DNA and protein during viral infection of bacteria.
**Why the Correct Answer is Right**
The experiment used bacteriophages (viruses that infect bacteria) labeled with radioactive isotopes: **³²P (phosphorus)** for DNA and **³⁵S (sulfur)** for protein. After infection, only the DNA (³²P) entered bacterial cells, while the protein coat (³⁵S) remained outside. This proved DNA carries genetic information.
**Why Each Wrong Option is Incorrect**
**Option A:** *Bacteria* — Incorrect. Bacteria were the host cells, not the experimental subject. The phage’s genetic material was studied.
**Option C:** *Yeast* — Incorrect. Yeast is a eukaryotic organism unrelated to this bacterial virus experiment.
**Option D:** *Algae* — Incorrect. Algae are not involved in phage experiments; the focus was on simple host-virus interactions.
**Clinical Pearl / High-Yield Fact**
Remember **“Phage DNA infects, protein stays outside”** as a mnemonic. This experiment directly refuted the protein-as-genetic-material hypothesis, a key point in molecular biology exams.
**Correct Answer: B. Bacteriophage**