1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jeka57 [31]
3 years ago
7

alfred hershey and martha chase designed an experiment to determine the chemical makeup of griffith's transforming principle. de

fine the term bacteriophage and explain why this organism was a good choice for this particular experiment. describe the procedure of the experiment using the terms bacteriophage, DNA, and proteins in your answer. Describe the results of the experiment and connect them to hershey and chases conclusion
Biology
1 answer:
MAXImum [283]3 years ago
5 0

Answer:

Bacteriophages (phages) are viruses that infect only bacteria and do not infect mammalian or plant cells. Phages are ubiquitous in the environment. Phages or bacteriophages were chosen as a model system for their simplicity, as they only contained protein-coated nucleic acid. Alfred D. Hershey and Martha Chase (who were part of the bacteriophage group) in 1952 studying the infection of the bacterium Escherichia coli by the T2 phage show that the information definitely resides in the DNA. They used phage with either [32P] -labeled DNA or [35S] -labeled proteins to infect the bacteria. Immediately afterwards, they centrifuged the sample so that the infected bacteria remain in the pellet and the virus capsids (proteins) remain in the supernatant. [35S] is found in the supernatant, whereas [32P] is found in bacteria. After one cycle of infection, it was observed that when phage labeled in the [35S] proteins were used, only 1% of the radioactivity was incorporated into the progeny. But when phages were [32P] labeled, more than 30% of the radioactivity was in the progeny. They showed directly that what is transmitted from one progeny to another is the DNA and not the proteins, despite having first "diluted" in a bacterium.

Explanation:

Bacteriophages are viruses that infect bacteria in a specific way. Bacteriophages, like other known viruses, are found in an intermediate zone between living organisms and inert matter. Bacteriophages bind to the host pathogenic bacterium, introduce their genetic material, replicate inside it and destroy it. Hersey, along with his assistant Martha Chase, used phages because they knew that T2 phages were made up of 50% proteins and 50% nucleic acids and that phages entered bacteria and reproduced. As the progeny carried the same infection traits, the genetic material of this had to be transmitted to the offspring, but the mechanism was unknown. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the bacterium Escherichia coli, which it reproduces by attaching itself to the outer wall of the bacterium, injecting its DNA into it where it replicates and directs the synthesis of the phage's own proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or disrupt the cell and release phage from progeny. They infected a culture of bacteria with radioactively labeled phages: the protein coat with sulfur (35S) and its DNA with phosphorus (32P). After infection, they separated the phages from the bacteria by violent shaking using a mixer (hence the name of the experiment). By centrifugation the much smaller phages remained in the supernatant and the much larger bacteria in the pellet. 85% of the radioactivity corresponding to DNA appeared in the pellet and 82% of the protein in the supernatant. This result supported the idea that DNA was the only component of the bacteriophage that penetrated the interior of the bacteria and, having the ability to form new phages, constituted the genetic material.

You might be interested in
What would be some alternative methods for girdling dicots?
34kurt

The answer is marcotting. This is for trees, shrubs and semi-woody plants. The two cuts are then connected by a straight cut and the bark is pried loose and removed. This involves pressing of a sharp knife against the bark preferably as close as possible below a node, moving the knife in circular motion around the stem.

6 0
3 years ago
These are fossils of a fish (vagrant pelagic vertebrate; sample a), and a coral (sessile benthic cnidarian; sample b). in genera
densk [106]
The coral fossil would be a better estimate of past water depth. This is because most corals inhabit shallow water reefs, less than 150 feet deep. In contrast, pelagic fish may inhabit any open water (pelagic) part of the ocean, with depths ranging anywhere from a couple of hundred feet deep to miles in depth.  
6 0
3 years ago
Prior to administering drug x to treat a patient's high blood pressure, the nurse reviews information about the drug. the nurse
kifflom [539]
<span>The property of this drug that would make it ideal is if it had something to void out the nausea and headache. Even though they aren't considered serious side effects, they can develop into a chronic problem if allowed.</span>
3 0
3 years ago
How is Bohr's atomic model different from Rutherford’s model?
Aleonysh [2.5K]
Answer is The second one
8 0
3 years ago
Read 2 more answers
Refers to the biological and anatomical differences between females and males.
Arturiano [62]
The answer is:  "sexual dimorphism" .
_____________________________________________________
7 0
3 years ago
Read 2 more answers
Other questions:
  • Is an organic compound that aids enzyme function by combining with an inactive enzyme to form a catalytically active form?
    14·1 answer
  • The ability of the kidneys to maintain a relatively constant GFR despite changes in blood pressure without the input of nervous
    9·1 answer
  • How do land animals create methane?
    8·1 answer
  • A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases, altho
    5·1 answer
  • 3) In mice, brown eyes (B) are dominant over blue (b). A homozygous brown-eyed male mouse mates with a blue-eyed female and they
    5·2 answers
  • What are the biological catalyst ?
    12·1 answer
  • Can anyone help me?
    11·1 answer
  • Air is made of ____and ____​
    5·2 answers
  • What process is talking place when moving water is carrying away small ppieces of rock
    6·2 answers
  • The soybean aphid was introduced to the United States in 2000. The aphid killed many soybean plants. In 2004, scientists
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!