What key experiments led to the discovery that DNA, rather than protein, is the genetic material in cells?
Oswald Avery's experiment in the 1940s showed that DNA from dead infectious bacteria could transform non-infectious bacteria, making them infectious. The Hershey-Chase experiments in the 1950s confirmed that DNA, not protein, was transferred to bacteria by viruses, proving DNA is the genetic material.
How did the Hershey-Chase experiment demonstrate that DNA is the genetic material of viruses?
The Hershey-Chase experiment labeled viral DNA and protein with different radioactive markers and found that only the DNA entered bacteria during infection, showing that DNA, not protein, carries genetic information.
Why was protein originally thought to be the genetic material instead of DNA?
Protein was thought to be the genetic material because it is made of 20 different amino acids, offering more complexity and variability than DNA, which has only four bases.
What was the significance of Watson and Crick's discovery of the DNA double helix structure?
Watson and Crick's discovery of the double helix structure explained how genetic information is stored, replicated, and inherited, providing a clear model for DNA's role as the genetic material.
How did Oswald Avery's experiment with mice demonstrate that DNA is the genetic material?
Avery showed that when mice were injected with a mixture of dead infectious bacteria and live non-infectious bacteria, the mice died because DNA from the dead bacteria transformed the live bacteria into an infectious form, indicating DNA carries genetic information.
Why was protein originally considered the genetic material instead of DNA?
Protein was thought to be the genetic material because it has 20 different amino acids, offering more complexity than DNA, which has only four bases.
What did Oswald Avery's experiment with mice demonstrate about DNA?
Avery's experiment showed that DNA from dead infectious bacteria could transform live non-infectious bacteria into an infectious form, indicating DNA carries genetic information.
How did the Hershey-Chase experiment confirm that DNA is the genetic material in viruses?
The Hershey-Chase experiment used radioactive labeling to show that only DNA, not protein, entered bacteria during viral infection, proving DNA is the genetic material.
What was the significance of Watson and Crick's discovery of the DNA double helix?
Their discovery explained how genetic information is stored, replicated, and inherited, providing a clear model for DNA's role as the genetic material.
In Avery's experiment, why did mice die when injected with both dead infectious and live non-infectious bacteria?
The DNA from the dead infectious bacteria transformed the live non-infectious bacteria into an infectious form, causing the mice to die.