Question

Chargaff discovered that the A-T bond has the same width as the G-C bond. What implication does this have for the structure of the DNA molecule?

It means that the molecule will vary in width as you move down its length, depending on the number of A-T and G-C nucleotides. It means that the molecule will be very hydrophilic, because nucleotides are hydrophilic. It means that DNA was the first life form on Earth. It means that the molecule will remain constant in width as you move down its length, independent of the number of A-T and G-C nucleotides. It means that the molecule will elongate upon exposure to water.

3.	Which of the following pieces of critical information did Watson and Crick use to build and propose their model of the structure of DNA?
	x-ray diffraction images that show DNA as a double helix All of the answers are correct. an incorrect model that depicts DNA as a triple helix with the phosphate groups on the inside %A always equals %T and %G always equals %C x-ray diffraction images that suggest DNA is hydrophilic and elongates upon exposure to water

4.	Rosalind Franklin used x-ray diffraction to record how x-rays scatter when bounced off the surface of DNA molecules. Which of the following conclusions about the structure of DNA did her images support?
	All of the answers are correct. The DNA helix was likely made of two strands. The DNA molecule was uniform in width. The DNA molecule was likely helical. The DNA molecule was hydrophilic and extends upon exposure to water.

5.	Rosalind Franklin did not receive the credit she deserves for her contribution to the discovery of the structure of DNA because _____.
	her paper was perceived merely as supporting evidence for Watson and Crick's model. she died before the Nobel Prize was awarded to Watson, Crick, and Wilkins All of the answers are correct. at the time, prevailing attitudes were negative toward women in science None of the answers is correct.

Answer 1

Chargaff discovered that the A-T bond has the same width as the G-C bond. What implication does this have for the structure of the DNA molecule?

- It means that the molecule will vary in width as you move down its length, depending on the number of A-T and G-C nucleotides.

3. Which of the following pieces of critical information did Watson and Crick use to build and propose their model of the structure of DNA?

- x-ray diffraction images that show DNA as a double helix, an incorrect model that depicts DNA as a triple helix with the phosphate groups on the inside, %A always equals %T and %G always equals %C, and x-ray diffraction images that suggest DNA is hydrophilic and elongates upon exposure to water.

All of the answers are correct.

4. Rosalind Franklin used x-ray diffraction to record how x-rays scatter when bounced off the surface of DNA molecules. Which of the following conclusions about the structure of DNA did her images support?

- The DNA helix was likely made of two strands, DNA molecule was uniform in width, DNA molecule was likely helical, and DNA molecule was hydrophilic and extends upon exposure to water.

All of the answers are correct.

5. Rosalind Franklin did not receive the credit she deserves for her contribution to the discovery of the structure of DNA because _____.
- her paper was perceived merely as supporting evidence for Watson and Crick's model, she died before the Nobel Prize was awarded to Watson, Crick, and Wilkins, and at the time, prevailing attitudes were negative toward women in science