Nucleic acids are polymers made up of nucleotide monomers. The differences between RNA and DNA include RNA containing ribose with an OH group, while DNA contains deoxyribose. Hydrogen bonds form between complementary bases on two DNA strands. During mRNA processing, introns are removed and exons are joined to form mature mRNA. Nucleic acids and proteins consist of repeating units linked by phosphodiester bonds in the backbone.

1. Bio 110 Practice problems (Chap 3 Part 4)
NUCLEIC ACIDS. Answers posted at the bottom of the page.
1. Nucleic acids are polymers made up of which of the following monomers?
A) nucleotides
B) sugars
C) amino acids
D) nitrogenous bases
2. What is the difference between ribonucleotides (in RNA) and deoxyribonucleotides (DNA)?
A) Ribonucleotides each contain a phosphate group, deoxyribonucleotides do not.
B) Ribonucleotides have a hydroxyl group (-OH) on the 2’ carbon of their sugar subunit.
C) Ribonucleotides contain a sugar with five carbon atoms, deoxyribonucleotides do not.
D) Ribonucleotides have a H atom at 1’ carbon of their sugars, deoxyribonucleotides do not.
3. What type of bonds form between the nucleotides of 2 complementary strands of DNA and
hold both strands together?
A) hydrogen bonds
B) covalent bonds
C) ionic bonds
D) polar covalent bonds
4. Which of the following statements are true about DNA?
A) The nucleic acid polynucleotide strand prefer to form a hairpin structure.
B) The nitrogenous bases are located on the outside of the double helix.
C) Bases on either strands of the double helix are complementary to each other.
D) Nucleotide monomers include A, U, G and C.
5. The molecule on the right is a/an ______, it forms hydrogen bonds with
a/an ______ in a double-helix.
A) pyrimidine, pyrimidine
B) pyrimidine, purine
C) purine, pyrimidine
D) purine, purine
6. Which of the following statements about Lactase Persistence (LP) is FALSE?
A) It arose in different geographic locations.
B) It arose in one geographic location and spred to other locations later on.
C) Several different mutations are known lead to lactase persistence.
D) People with lactase persistence are able to digest milk sugar, lactose, into adulthood.

2. Bio 110 Practice problems (Chap 3 Part 4)
7. The diagram below shows Cytosine (C) and Guanine (G) on 2 different strands of DNA.
(a) Indicate (with proper notation for hydrogen
bonds) on the diagram the location of hydrogen
bonds that aid in formation of double-helix.
8. A peptide bond in proteins is analogous to which of the following in nucleic acids?
A) an amino group
B) a peptide bond
C) a hydrogen bond
D) phosphodiester bond
9. True / False (Circle one) DNA and RNA consist of repeating units of sugar-base-
phosphate in its backbone.
10.(a) If the proportion of Thymine (T) bases in the DNA double-helix of an organism is
15%, what is the proportion of Adenine (A) bases in the same organism?
(b) In the question in 10(a), for the same organism, what is the proportion of Guanine
(G) in its DNA?
(b) How many hydrogen bonds would you expect
to see between the 2 molecules on the left?

3. Bio 110 Practice problems (Chap 3 Part 4)
11. Select the type of polymer structure shown for A and B. Circle the correct answer.
12. What happens to mRNA before it becomes “mature mRNA”?
A. The exons are removed and introns are joined to form mature mRNA.
B. The introns are removed and exons are joined to form mature mRNA.
C. Both exons and introns are removed to form mature mRNA.
D. All exons and introns are joined to form mature mRNA.
13. The figure below shows 4 categories of organic compounds you learned in Chapter 3.
Identify them according to the categories: Protein, Carbohydrate, Nuclei Acid and Lipid.
B is a (circle one):
Carbohydrate /
Lipid /
Nucleic Acid /
Protein
A is a (circle one):
Carbohydrate /
Lipid /
Nucleic Acid /
Protein

4. Bio 110 Practice problems (Chap 3 Part 4)