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AP Biology Practice Quiz: Lipids

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 9 questions to check your progress.

Question 1 of 9

Which of the following best describes the fundamental chemical property of lipids?

All Questions (9)

Which of the following best describes the fundamental chemical property of lipids?

A) They are nonpolar and hydrophobic.

B) They are polar and hydrophilic.

C) They readily dissolve in water.

D) They are assembled from amino acids.

Correct Answer: A

The provided content explicitly states, 'Lipids are nonpolar, hydrophobic molecules.' This means they do not mix well with water.

What structural feature distinguishes an unsaturated fatty acid from a saturated fatty acid?

A) The number of carbon atoms in the chain.

B) The presence of at least one double bond.

C) The presence of a glycerol backbone.

D) The absence of a carboxyl group.

Correct Answer: B

According to the text, saturated fatty acids have 'all single bonds,' while unsaturated fatty acids have 'at least one double bond' in their hydrocarbon chains.

According to the text, which class of lipids is primarily responsible for providing the main structural component of cell membranes?

A) Fats

B) Steroids

C) Phospholipids

D) Saturated fatty acids

Correct Answer: C

The content specifies that phospholipids perform diverse functions, including 'structural support in membranes.'

The distinction between saturated and unsaturated fatty acids, based on the type of carbon-carbon bonds present, directly influences which of the following?

A) The lipid's role in cell signaling.

B) The amount of energy stored per gram.

C) The lipid's physical properties.

D) The lipid's nonpolar nature.

Correct Answer: C

The text states that the presence of single or double bonds in fatty acids is a factor 'affecting their physical properties.'

A researcher is studying molecules involved in intercellular communication. Which class of lipids would be most relevant to this field of study?

A) Fats

B) Phospholipids

C) Steroids

D) Unsaturated fatty acids

Correct Answer: C

The provided content identifies steroids as the class of lipids that performs the function of 'cell signaling.'

Based on the provided information, which of the following is NOT a described function of lipids?

A) Long-term energy storage

B) Providing insulation

C) Encoding genetic information

D) Forming structural parts of membranes

Correct Answer: C

The text lists energy storage, insulation, cell signaling, and structural support in membranes as lipid functions. Encoding genetic information is the primary role of nucleic acids, not lipids.

Lipids are large biological molecules that are typically assembled from smaller subcomponents such as:

A) Monosaccharides

B) Amino acids

C) Nucleotides

D) Fatty acids

Correct Answer: D

The content explicitly mentions that lipids 'are assembled from subcomponents like fatty acids.'

A certain type of lipid is used by animals for both long-term energy storage and insulation. This type of lipid is best classified as a:

A) Fat

B) Steroid

C) Phospholipid

D) Hydrophilic molecule

Correct Answer: A

The text groups 'fats' with the functions of 'energy storage' and 'insulation.'

The ability of phospholipids to form the primary structure of cell membranes is a direct consequence of which fundamental property mentioned in the text?

A) Their ability to store large amounts of energy.

B) Their classification as either saturated or unsaturated.

C) Their function in cell signaling pathways.

D) Their nonpolar, hydrophobic nature.

Correct Answer: D

The text establishes that lipids are nonpolar and hydrophobic, and that phospholipids provide structural support in membranes. The hydrophobic property is what drives the self-assembly of the lipid bilayer, which forms the membrane's structure.