Science 9-10 Molecular Structure

Science 9-10 Molecular Structure

Standards & Objectives

Essential and guiding questions: 
  • The article is titled “A Structure for Deoxyribose Nucleic Acid,” although we learned in class that DNA is an abbreviation for Deoxyribonucleic acid. What does the name of DNA say about the molecules contained within it?
  • Based upon your answer to #1, which version of the name for DNA is more correct (Deoxyribose nucleic acid or Deoxyribonucleic acid)? Explain your answer citing evidence from the text to support your choice.
  • In the opening paragraphs of the article, Watson and Crick make short work in dismissing the structures for DNA proposed by Pauling and Corey (1953), Fraser (1953), and Furberg (1952). What was the key issue Watson and Crick deemed unacceptable with each one of the aforementioned structures? (*This question also begins preparing students for the writing prompt).
  • In paragraph 5 (in the second column), Watson and Crick note, “At lower water contents we would expect the bases to tilt so that the structure would become more compact.” Which form of DNA are the scientists describing? Explain the prior knowledge and/or 
  • additional research used to determine your answer.
  • Why do Watson and Crick believe it would be “impossible” to build DNA with a ribose sugar in place of the deoxyribose sugar? Were they correct in this assumption? Back up your response by citing evidence from the article and providing reasoning to support your evidence.
  • INFER: Based purely upon classroom discussions and the information included within this article, connect the two following quotes from the article and use them to devise a possible mechanism for DNA replication: “…if only specific pairs of bases can be formed, it follows that if the sequence of bases on one chain is given, then the sequence on the other chain is automatically determined…” and “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”

Activity/Task Variations

Blooms taxonomy level: 
Differentiation suggestions: 

Scaffolding and support for special education students, English language learners, and struggling readers:

  • Vocabulary scaffolding will be necessary. Students will need clarification on the domain-specific and supporting academic language stated above.
  • Pre-reading activities such as underlining & looking up unknown words will be helpful. 3-D models of the previously learned DNA structure may also help students visualize as they read.