DNA Structure and Function Concepts

The video explores the discovery of DNA as the hereditary material, starting with early misconceptions about proteins being the genetic material. It covers key experiments by Griffith, Avery, McLeod, McCarty, and Hershey-Chase, which demonstrated DNA's role in heredity. The video also discusses Chargaff's rules and Rosalind Franklin's contributions to understanding DNA's structure, leading to Watson and Crick's model.

Why did scientists initially believe proteins were the genetic material instead of DNA?

• DNA is found only in some organisms.

• DNA was not discovered yet.

• Proteins are more complex than DNA.

• Proteins are easier to study.

What was the key finding from Griffith's experiment with pneumonia-causing bacteria?

• DNA is not involved in heredity.

• Viruses are the cause of pneumonia.

• Bacteria can transform from non-virulent to virulent.

• Proteins are the genetic material.

What did Avery, McLoud, and McCarty conclude about the transforming substance?

• It was DNA.

• It was a type of carbohydrate.

• It was a type of protein.

• It was a lipid.

Why were some scientists skeptical of Avery, McLoud, and McCarty's conclusion?

• They thought the experiment was flawed.

• They believed proteins were still involved.

• They had no evidence of DNA's role.

• They believed DNA was too simple.

What was the significance of Hershey and Chase's experiment?

• It showed viruses are made of DNA.

• It provided strong evidence that DNA is the genetic material.

• It proved proteins are the genetic material.

• It demonstrated that bacteria can be infected by viruses.

How did Hershey and Chase label the DNA in their experiment?

• With radioactive phosphorus.

• With radioactive sulfur.

• With heavy metals.

• With fluorescent dyes.

What did Chargaff discover about the composition of DNA?

• The amount of adenine equals the amount of thymine.

• DNA is composed of proteins.

• The amount of guanine equals the amount of adenine.

• DNA is identical in all species.

What technique did Rosalind Franklin use to study DNA?

• X-ray crystallography

• Electron microscopy

• Nuclear magnetic resonance

• Ultraviolet spectroscopy

What was the contribution of Watson and Crick to the understanding of DNA?

• They found DNA is composed of lipids.

• They proved DNA is not the genetic material.

• They identified the double helix structure of DNA.

• They discovered DNA is a protein.

Who was awarded the Nobel Prize for the discovery of the DNA structure?

• Rosalind Franklin

• Frederick Griffith

• Watson, Crick, and Wilkins

• Avery, McLoud, and McCarty