The four nitrogenous bases commonly found if DNA are:  
a) Adenine, thymine, cytosine, uracil 
b) Uracil, adenine, cytosine, guanine.
c) Uracil, cytosine, guanine, thymine.
d) Adenine, thymine, cytosine, guanine.
e) None are correct.

Which of the following is not part of a nucleotide?

a. An amino acid

b. A nitrogenous base

c. One or more phosphate groups

d. A sugar

Mark the following properties as belonging to either DNA or RNA.

a. Contains the nucleotides A, G, C, and U ____          

b. Found only in the nucleus of the cell   ____       

c. Can move in and out of the cell's nucleus ____         

d. Contains two strands of nucleotides linked by hydrogen bonds____          

e. Contains the code for every protein in the body____          

f. Contains the sugar ribose____          

The drug methotrexate is used to treat several different types of cancer and diseases of the immune system. It works by inhibiting an enzyme in the cell necessary for folic acid synthesis. Without folic acid, the cell cannot make nucleotides. What, specifically, does an enzyme do in the cell? Why would inhibiting this enzyme disrupt folic acid synthesis? What effect would a disruption in folic acid synthesis have on the cell as a whole? (Hint: Think about the role that folic acid plays in the cell.) (Connects to Chapter 2)

Which of the following descriptions best fits the class of molecules known as nucleotides?

a) A nitrogenous base & a phosphate group.

b) A nitrogenous base & a sugar.

c) A nitrogenous base, phosphate group & a sugar.

d) A nitrogenous base, a carbohydrate, & a sugar.

Which of the following statements about DNA structure is true?

a) The nucleic acid strands in a DNA molecule are oriented antiparallel to each other.

b) Nucleic acids are formed through phosphodiester bonds that link complementary nucleobases together.

c) Hydrogen bonds formed between the sugar-phosphate backbones of the two DNA chains stabilize the structure.

d) The pentose sugar in DNA is ribose (containing two hydroxyl groups).