---
title: "AP Biology Guided Practice"
description: "Fiveable has 26,558 AP Biology multiple-choice practice questions across 8 units, plus 455 stimulus-based question sets built around a source. Practice one unit or topic at a time."
canonical: "https://fiveable.me/ap-bio/guided-practice"
type: "guided-practice"
subject: "AP Biology"
---

# AP Biology Guided Practice

## Overview

Fiveable has 26,558 AP Biology multiple-choice practice questions across 8 units, plus 455 stimulus-based question sets built around a source. Practice one unit or topic at a time.

## Practice Questions by Unit

- Unit 1 – Chemistry of Life: 1,629 multiple-choice questions, 56 stimulus sets
- Unit 2 – Cell Structure and Function: 4,474 multiple-choice questions, 81 stimulus sets
- Unit 3 – Cellular Energetics: 2,352 multiple-choice questions, 37 stimulus sets
- Unit 4 – Cell Communication and Cell Cycle: 2,763 multiple-choice questions, 42 stimulus sets
- Unit 5 – Heredity: 2,183 multiple-choice questions, 38 stimulus sets
- Unit 6 – Gene Expression and Regulation: 3,416 multiple-choice questions, 61 stimulus sets
- Unit 7 – Natural Selection: 5,618 multiple-choice questions, 89 stimulus sets
- Unit 8 – Ecology: 4,123 multiple-choice questions, 51 stimulus sets

## Sample Question

A mutation prevents a cell from producing functional cyclin-dependent kinase (CDK), but cyclin proteins are still made. What effect on the cell cycle is most likely?

- (A) Cells fail to pass key checkpoints because cyclin-CDK complexes cannot phosphorylate targets
- (B) Cells speed through key checkpoints because cyclins alone can activate DNA replication proteins
- (C) Cells bypass key checkpoints because loss of CDK eliminates all checkpoint signaling proteins entirely
- (D) Cells complete normal mitosis because CDK is required only for cytokinesis, not checkpoints

**Answer: (A)** Linking checkpoint control to cyclin-CDK activity explains the disruption. Without functional CDK, cyclins cannot activate the kinase activity needed to phosphorylate proteins that drive progression through G1/S and G2/M checkpoints.

## Related Practice

- [Experimental Results FRQ practice: Interpreting and Evaluating Experimental Results question questions scored by part](/ap-bio/frqs/experimental-results)
- [Graphing FRQ practice: Interpreting and Evaluating Experimental Results with Graphing question questions scored by part](/ap-bio/frqs/graphing)
- [Scientific Investigation FRQ practice: Scientific Investigation question questions scored by part](/ap-bio/frqs/scientific-investigation)
- [Conceptual Analysis FRQ practice: Conceptual Analysis question questions scored by part](/ap-bio/frqs/conceptual-analysis)
- [Model Analysis FRQ practice: Analyze Model or Visual Representation question questions scored by part](/ap-bio/frqs/model-analysis)
- [Data Analysis FRQ practice: Analyze Data question questions scored by part](/ap-bio/frqs/data-analysis)
- [AP Biology unit tests: a timed practice test for every unit](/ap-bio/unit-test)
- [AP Biology full-length practice exams](/ap-bio/practice-exams)
- [AP Biology subject hub](/ap-bio)

## About This Document

Canonical Fiveable pages are available as Markdown at the same path plus `.md`.

- [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns
- [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing
- [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`)
- [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`)