11.2 Total D

11. How many pages was Watson and Crick's revolutionary DNA paper?

• Ten pages
• Five pages
• Three pages
• One page

12. What did scientists initially think DNA was in the 1940s?

• A complex protein structure
• A simple string of nucleotides
• A triple helix
• A cellular membrane

13. What comparison did scientists make between DNA nucleotides and language?

• They compared bases to paragraphs
• They compared nucleotides to words
• They compared bases to letters of the alphabet
• They compared sequences to sentences

14. What was significant about Chargaff's findings across different organisms?

• Only bacteria followed the base-pairing rule
• The rule only applied to mammals
• Different organisms had different rules
• The rule applied to organisms from bacteria to humans

15. How did Franklin prepare DNA samples for X-ray diffraction?

• She dissolved them in solution
• She stretched them in a thin glass tube
• She crystallized them
• She froze them

16. What property of DNA initially puzzled scientists about its ability to carry information?

• Its simple structure
• Its complex structure
• Its variable sequence possibilities
• Its molecular weight

17. How are the nucleotides commonly referred to by biologists?

• By their full names only
• By their chemical formulas
• By their first letters (A, G, C, T)
• By their molecular weights

18. What is the relationship between nucleic acids and nucleotides?

• They are the same thing
• Nucleotides are made of nucleic acids
• Nucleic acids are built from nucleotide monomers
• They are unrelated molecules

19. What aspect of DNA structure allows for genetic information storage?

• The sugar-phosphate backbone
• The variable sequence of bases
• The double helix shape
• The molecular weight

20. How did Watson describe his reaction to seeing Photo 51?

• He was confused and frustrated
• He was skeptical and doubtful
• His mouth fell open and his pulse began to race
• He remained calm and collected