Discovery of DNA/Structure of DNA

How was the structure of DNA discovered?

• By building a model of a twisted ladder

• By studying the cell membrane

• By measuring cell energy

• By analyzing proteins

Which pair of scientists built the famous DNA model in 1953?

• Watson and Crick

• Franklin and Wilkins

• Chargaff and Watson

• Crick and Chargaff

What technique did Rosalind Franklin use to study DNA?

• X-ray diffraction

• Electron microscopy

• Chemical titration

• DNA sequencing

Rosalind Franklin’s X-ray images of DNA revealed that its strands are arranged like:

• A twisted ladder (double helix)

• A straight line

• A circular ring

• A random coil

Who showed Watson the X-ray images that helped reveal the structure of DNA?

• Maurice Wilkins

• Erwin Chargaff

• Francis Crick

• James Watson

What did Erwin Chargaff discover about the bases in DNA?

• The amounts of adenine equal thymine and guanine equal cytosine

• All bases are present in equal amounts

• DNA contains only two bases

• Bases are not important for DNA function

Which of the following is a concern about academic integrity in the discovery of DNA?

• Franklin’s data was shared without her permission

• Lab equipment was stolen

• Data was completely falsified

• There was no collaboration among scientists

Which scientist’s work was crucial but received less credit?

• James Watson

• Rosalind Franklin

• Francis Crick

• Erwin Chargaff

What did the X-shaped pattern in Franklin's X-ray diffraction image indicate?

• DNA is flat

• DNA strands are twisted like a spiral staircase

• DNA is made of protein

• DNA is a circle

DNA is made of repeating units called:

• Nucleotides

• Amino acids

• Proteins

• Lipids