Table of contents

1. Introduction to Biology2h 42m
2. Chemistry3h 37m
3. Water1h 26m
4. Biomolecules2h 23m
5. Cell Components2h 26m
6. The Membrane2h 31m
7. Energy and Metabolism2h 0m
8. Respiration2h 40m
9. Photosynthesis2h 49m
10. Cell Signaling59m
11. Cell Division2h 47m
12. Meiosis2h 0m
13. Mendelian Genetics4h 44m
14. DNA Synthesis2h 27m
15. Gene Expression3h 6m
16. Regulation of Expression3h 31m
17. Viruses37m
- Viruses
  37m
18. Biotechnology2h 58m
19. Genomics17m
- Genomes
  17m
20. Development1h 5m
21. Evolution3h 1m
22. Evolution of Populations3h 53m
23. Speciation1h 37m
24. History of Life on Earth2h 6m
25. Phylogeny2h 31m
26. Prokaryotes4h 59m
27. Protists1h 12m
28. Plants1h 22m
29. Fungi36m
- Fungi
  19m
- Fungi Reproduction
  17m
30. Overview of Animals34m
- Overview of Animals
  34m
31. Invertebrates1h 2m
32. Vertebrates50m
33. Plant Anatomy1h 3m
34. Vascular Plant Transport1h 2m
- Water Potential
  1h 2m
35. Soil37m
- Soil and Nutrients
  20m
- Nitrogen Fixation
  16m
36. Plant Reproduction47m
- Flowers
  33m
- Seeds
  14m
37. Plant Sensation and Response1h 9m
38. Animal Form and Function1h 19m
39. Digestive System1h 10m
- Digestion
  1h 3m
- Blood Sugar Homeostasis
  7m
40. Circulatory System1h 49m
41. Immune System1h 12m
42. Osmoregulation and Excretion50m
- Osmoregulation and Excretion
  50m
43. Endocrine System1h 4m
- Endocrine System
  1h 4m
44. Animal Reproduction1h 2m
- Animal Reproduction
  1h 2m
45. Nervous System1h 55m
- Neurons and Action Potentials
  1h 8m
- Central and Peripheral Nervous System
  46m
46. Sensory Systems46m
- Sensory System
  46m
47. Muscle Systems23m
- Musculoskeletal System
  23m
48. Ecology3h 11m
49. Animal Behavior28m
- Animal Behavior
  28m
50. Population Ecology3h 41m
51. Community Ecology2h 46m
52. Ecosystems2h 36m
53. Conservation Biology24m
- Conservation Biology
  24m

14. DNA Synthesis

The Hershey-Chase Experiment

General Biology

14. DNA Synthesis

The Hershey-Chase Experiment

Previous problemNext problem

0:41 minutes

Problem 12

Textbook Question

The success of an experiment often depends on choosing an appropriate organism to study. For example, Gregor Mendel was able to deduce the fundamental principles in genetics in part because of his choice of the pea plant. Reviewing Module 10.1, how did Hershey and Chase take advantage of the unique structural properties of bacteriophage T2 to determine the genetic material?

Verified step by step guidance

Review the structure of bacteriophage T2: Bacteriophage T2 is a virus that infects bacteria. It consists of a protein coat (capsid) and DNA inside the capsid. This structural simplicity makes it an ideal organism for studying the genetic material, as it has only two main components to analyze: protein and DNA.

Understand the experimental design: Hershey and Chase used radioactive isotopes to label the two components of the bacteriophage. They labeled the DNA with radioactive phosphorus-32 (32P), since DNA contains phosphorus but no sulfur. They labeled the protein coat with radioactive sulfur-35 (35S), since proteins contain sulfur but no phosphorus.

Describe the infection process: The bacteriophage attaches to a bacterial cell and injects its genetic material into the host. The protein coat remains outside the bacterial cell, while the genetic material enters the cell to direct the production of new viruses.

Explain the separation of components: After allowing the bacteriophages to infect the bacteria, Hershey and Chase used a blender to separate the phage protein coats from the bacterial cells. They then used a centrifuge to isolate the bacterial cells from the rest of the mixture.

Analyze the results: They measured the radioactivity in the bacterial cells and the surrounding solution. They found that the radioactive phosphorus (32P) was inside the bacterial cells, indicating that DNA was the genetic material injected by the phage. The radioactive sulfur (35S) remained in the solution, showing that the protein coat did not enter the bacterial cells.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

41s

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Bacteriophage Structure

Bacteriophages, or phages, are viruses that specifically infect bacteria. The T2 bacteriophage consists of a protein coat (capsid) and a DNA core. This simple structure allows researchers to study the role of DNA in heredity, as the phage injects its genetic material into the host bacterium, leading to the production of new phages.

Hershey-Chase Experiment

The Hershey-Chase experiment, conducted in 1952, utilized T2 bacteriophages to determine whether DNA or protein was the genetic material. By labeling the DNA with radioactive phosphorus and the protein with sulfur, they tracked which component entered the bacterial cells. The results showed that only the DNA entered the cells, confirming that DNA is the genetic material.

Genetic Material

Genetic material refers to the molecules that carry the genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses. In most organisms, this material is DNA, which encodes the information necessary for building proteins and regulating cellular activities. The identification of DNA as the genetic material was a pivotal moment in molecular biology.

Watch next

Master Bacteriophages with a bite sized video explanation from Jason

Start learning

Related Videos

Related Practice

Multiple Choice

In an important experiment, a radioactively labeled bacteriophage was allowed to infect bacteria. In a first trial, the phage contained radioactive DNA, and radioactivity was detected inside the bacteria. Next, phage-containing radioactive protein was used, and the radioactivity was not detected inside the bacteria. These experiments led to the conclusion that __________.

1732

views

Multiple Choice

Which of the following considerations was/were important in the choice of viruses and bacteria for early experiments on DNA?

870

views

Textbook Question

Researchers design experiments so that only one thing is different between the treatments that are being compared. In the Hershey–Chase experiment, what was this single difference?

665

views

Textbook Question

Scientists have discovered how to put together a bacteriophage with the protein coat of phage T2 and the DNA of phage lambda. If this composite phage were allowed to infect a bacterium, the phages produced in the host cell would have _________. (Explain your answer.)

a. The protein of T2 and the DNA of lambda

b. The protein of lambda and the DNA of T2

c. The protein and DNA of T2

d. The protein and DNA of lambda

1435

views

Multiple Choice

Who demonstrated that DNA is the genetic material of the T2 phage in the Hershey-Chase experiment?

297

views

Multiple Choice

Hershey and Chase set out to determine what molecule served as the unit of inheritance. Which molecular component of the T2 virus actually ended up inside the cell?

Choose the incorrect statement about the results of the Hershey-Chase Experiment.

Which of the following facts did Hershey and Chase make use of in trying to determine whether DNA or protein is the genetic material?

4488

views