AP Biology Unit 1 Nucleic Acids

Which of the following element(s) are found in nucleic acids?

• Carbon / Hydrogen

• Oxygen

• Phosphorus

• Nitrogen

• Sulfur

Which of the following is the monomer of a nucleic acid?

• Amino acid

• Monosaccharide

• Nucleotide

• Nitrogenous base

Which of the following is NOT one of the three comprising the nucleotide?

• R group

• Phosphate

• Nitrogenous base

• Pentose sugar

Which of the following describes the difference between a purine and a pyrimidine?

• Purines are single ring structures while pyrimidines are double ring structures

• Pyrimidines are single ring structures while purines are double ring structures

• Purines are composed of single bonds while pyrimidines are composed of double bonds

• Pyrimidines are composed of single bonds while purines are composed of double bonds

Which of the following are purines?

• Adenine

• Cytosine

• Guanine

• Thymine

• Uracil

Which of the following are pyrimidines?

• Adenine

• Cytosine

• Guanine

• Thymine

• Uracil

Which of the following describes the base pairing and bonding involved with nitrogenous bases?

• Adenine binds with cytosine with two hydrogen bonds

• Adenine binds with thymine with two hydrogen bonds

• Adenine binds with guanine with three hydrogen bonds

• Adenine binds with uracil with three hydrogen bonds

Which of the following describes a DNA strand that would be most stable at high temperatures?

• 25% A/T and

  75% G/C

• 50% A/T and

  50% G/C

• 75% A/T and

  25% G/C

• 100% A/T and

  0% G/C

Answer explanation

G/C bonds are stronger than A/T bonds because they have 3H bonds

If a researcher investigating a RNA strand discovers it contains 36% uracil, which of the following identifies the amount of cytosine?

• 14%

• 28%

• 64%

• Cannot be determined

Answer explanation

RNA is single stranded, so there is not a matched strand to base the rest of the sequence off of

Which of the following describes the directionality of nucleic acids?

• 5' end has a hydroxyl and 3' end has a phosphate

• 5' end has a phosphate and 3' end has a hydroxyl

• 5' end has an amino group and 3' end has a carboxyl group

• 5' end has a carboxyl group and 3' end has an amino group