4. The base content of a particular DNA molecule is 24% G. What is the percentage of the following bases in the molecule? %A: % T: % C: 5. What is the structural difference between the pentose sugars in DNA and RNA? 6. Why is the AT base pair less stable than the GC base pair?

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6. In RNA, why can uracil be used in place of thymine? * The structural difference between thymine and uracil does not affect hydrogen bonding to adenine Thymine and uracil are actually identical bases, but they're named differently because one is in DNA and the other is in RNA Uracil forms two hydrogen bonds with adenine, but using different atoms than thymine O Uracil can interact with adenine via three hydrogen bonds 7. At least how many different types of RNA are there in eukaryotic cells? * 1: just messenger RNA 2: messenger RNA and ribosomal RNA 3: messenger RNA, ribosomal RNA, and transfer RNA 6: the three listed above in C, plus microRNA, small interfering RNA, and small nuclear RNA 1

47. Define, in the context of DNA structure, "topological bonds."

5. Draw a DNA polymer with three nucleotides by including the following nitrogenous bases [in the following positions]: adenine [5' end], guanine [middle], and cytosine [3' end]. Draw only one strand. a. Indicate if each of the nitrogenous bases is a purine or pyrimidine. b. Number the carbons on the middle sugar. c. Label the phosphodiester bonds between the nucleotide in the middle and 3' end. d. Write the structure of the complementary sequence by indicating proper orientation.

13. The monomer of a nucleic acid? polymer of a nucleic acid? 14. What two main functions do nucleic acids have? а. b. 15. What are the three parts that make up a nucleotide? а. Draw a basic nucleotide. b. с. 16. What kind of bond holds the two strands of a DNA double helix together?

11. Match each statement below to the appropriate nucleotide. The options include A, I, C, G, U, and BOTH T & U. Some statements may refer to the images shown below: I. II. NH2 III. O V. NH2 IV. NH N. NH N NH N NH, N A a. The base shown in image I. b. The complimentary pair(s) to the base shown in image IV. c. The base(s) that form a complimentary pair with guanine. d. The base shown in image III. e. The base(s) that form a complimentary pair with adenine. f. The base shown in image V. T C G U BOTH T & U