Unit 1: Chemistry of Life

AP Biology — 11 practice questions with detailed explanations. Use the links below to open each full question page (ideal for search indexing and deep study).

Unit summary

This unit covers core ideas tested on the AP exam. Each listed item links to a standalone page with the full stem, answer choices where applicable, a step-by-step explanation, and the correct answer. Difficulty labels help you prioritize review.

Questions in this unit

Water molecules form hydrogen bonds with each other and with solutes. Which of the following statements best explains how these hydrogen bonds contribute to water's high specific heat capacity and ability to moderate temperature changes?medium · mcq · 1 pt
Which property of water most directly enables organisms to maintain relatively stable internal temperatures despite environmental fluctuations?medium · mcq · 1 pt
Humans can digest starch but not cellulose because:medium · mcq · 1 pt
When oil is added to water, it forms discrete droplets rather than dissolving. This behavior occurs because:medium · mcq · 1 pt
Which of the following correctly distinguishes DNA from RNA?easy · mcq · 1 pt
A mutation causes a hydrophobic amino acid in the interior of a protein to be replaced with a hydrophilic amino acid. The loss of protein function is primarily due to disruption of:easy · mcq · 1 pt
During the formation of a triglyceride from glycerol and three fatty acids, three water molecules are produced. This type of reaction is an example of:medium · mcq · 1 pt
Which element is found in amino acids but is generally absent from simple carbohydrates and lipids?easy · mcq · 1 pt
The ability of water molecules to form hydrogen bonds contributes to all of the following properties EXCEPT:hard · mcq · 1 pt
A researcher treats a purified protein solution with a chemical that specifically disrupts hydrogen bonds but does not break covalent bonds. Which levels of protein structure would be MOST directly affected?medium · mcq · 1 pt
Which of the following best explains why water has a significantly higher boiling point than hydrogen sulfide (H₂S), despite both being small polar molecules?hard · mcq · 1 pt

Sample prompts

Short previews of topics covered (not full question text).

Water molecules form hydrogen bonds with each other and with solutes. Which of t…
Which property of water most directly enables organisms to maintain relatively s…
Humans can digest starch but not cellulose because:…
When oil is added to water, it forms discrete droplets rather than dissolving. T…
Which of the following correctly distinguishes DNA from RNA?…
A mutation causes a hydrophobic amino acid in the interior of a protein to be re…
During the formation of a triglyceride from glycerol and three fatty acids, thre…
Which element is found in amino acids but is generally absent from simple carboh…
The ability of water molecules to form hydrogen bonds contributes to all of the …
A researcher treats a purified protein solution with a chemical that specificall…
Which of the following best explains why water has a significantly higher boilin…