---
title: "AP Biology Required Labs"
description: "Review the AP Biology investigative labs and the CED concepts, data skills, and lab reasoning they support."
canonical: "https://fiveable.me/ap-bio/required-labs"
type: "unit"
subject: "AP Biology"
unit: "Required Labs"
---

# AP Biology Required Labs

## Overview

This page collects all 13 AP Biology required lab guides in one place. Each guide explains the core question the lab answers, the data skills it tests, and the exam connections you need to know. Use this page when you are reviewing for the AP exam and want to make sure you can interpret lab data, not just recall vocabulary.

## AP CED Alignment

This unit hub is organized around AP Course and Exam Description topics, skills, and exam task types when they are available in the source data.
- Lab 1: Artificial Selection
- Lab 2: Mathematical Modeling: Hardy-Weinberg
- Lab 3: Comparing DNA Sequences to Understand Evolutionary Relationships with BLAST
- Lab 4: Diffusion and Osmosis
- Lab 5: Photosynthesis
- Lab 6: Cellular Respiration
- Lab 7: Cell Division: Mitosis and Meiosis
- Lab 8: Biotechnology: Bacterial Transformation
- Lab 9: Biotechnology: Restriction Enzyme Analysis of DNA
- Lab 10: Energy Dynamics
- Lab 11: Transpiration
- Lab 12: Fruit Fly Behavior
- Lab 13: Enzyme Activity
- Lab review: Choosing and sequencing your lab review

## Topics

- [Lab 1: Artificial Selection](/ap-bio/required-labs/artificial-selection/study-guide/cyqdArpgong5HkwDVOKG): Track how human selection changes phenotype frequencies across generations. This review connects variation, heritable traits, fitness, population change, and data-based claims about evolution by selection.
- [Lab 2: Mathematical Modeling: Hardy-Weinberg](/ap-bio/required-labs/mathematical-modeling-hardy-weinberg/study-guide/CcqDl5B5cDHDS6gNFbFf): Use Hardy-Weinberg equations as a null model for a non-evolving population. The guide reviews allele frequency, genotype frequency, expected values, chi-square reasoning, and what it means when data do not fit equilibrium.
- [Lab 3: Comparing DNA Sequences to Understand Evolutionary Relationships with BLAST](/ap-bio/required-labs/blast-evolutionary-relationships/study-guide/MiDP8CtCAAYNQW3GMFFc): Use DNA sequence similarity to infer relatedness and build evolutionary claims. This review focuses on BLAST evidence, molecular homology, phylogenetic trees, cladograms, and using sequence data to support common ancestry.
- [Lab 4: Diffusion and Osmosis](/ap-bio/required-labs/diffusion-and-osmosis/study-guide/451ICyd52ERQXgqDF7Gs): Predict and measure water movement across selectively permeable membranes. The review covers concentration gradients, tonicity, water potential, percent mass change, and using osmosis data to identify an unknown solution.
- [Lab 5: Photosynthesis](/ap-bio/required-labs/photosynthesis/study-guide/FmbGOzpHyNvOVnobkMKF): Measure how light conditions affect the rate of photosynthesis. This guide connects chlorophyll, light reactions, carbon fixation, primary productivity, and graph-based evidence about how producers capture energy.
- [Lab 6: Cellular Respiration](/ap-bio/required-labs/cellular-respiration/study-guide/HpNsD38c4CNHRJw7pIKr): Measure respiration rate from oxygen consumption or carbon dioxide production. The review connects ATP production, electron transport, fermentation, temperature or substrate effects, and rate data from living systems.
- [Lab 7: Cell Division: Mitosis and Meiosis](/ap-bio/required-labs/cell-division-mitosis-and-meiosis/study-guide/sDu1xUpEGLBh4b1jHo7B): Use observations and calculations to connect cell division to growth and genetic variation. This guide reviews mitotic index, cell cycle evidence, crossing over, independent assortment, and how meiosis creates different gametes.
- [Lab 8: Biotechnology: Bacterial Transformation](/ap-bio/required-labs/bacterial-transformation/study-guide/JtXuo2FXIYgYuM3x3fji): Explain how plasmids can change bacterial phenotype and how selection plates reveal transformation. The review covers gene expression, selectable markers, controls, transformation efficiency, and evidence from colony growth.
- [Lab 9: Biotechnology: Restriction Enzyme Analysis of DNA](/ap-bio/required-labs/restriction-enzyme-analysis-of-dna/study-guide/Lao7by8PdZl2yD3nlSd0): Use restriction enzymes and gel electrophoresis patterns to analyze DNA. This guide connects sequence-specific cutting, fragment size, DNA structure, restriction maps, and evidence-based identification of DNA samples.
- [Lab 10: Energy Dynamics](/ap-bio/required-labs/energy-dynamics/study-guide/wq1NFweZrh5EpuAHEF9u): Model how energy moves through ecosystems and why less energy is available at higher trophic levels. The review covers primary productivity, ecological efficiency, carrying capacity, community effects, and ecosystem resilience.
- [Lab 11: Transpiration](/ap-bio/required-labs/transpiration/study-guide/Vf2CqCP0Uy63c0MJoDc3): Measure plant water loss and explain it with water potential and stomatal regulation. This guide connects osmosis, transpiration rate, environmental variables, plant transport, and the hydrologic cycle.
- [Lab 12: Fruit Fly Behavior](/ap-bio/required-labs/fruit-fly-behavior/study-guide/t4XYRnAN2gY45Gw58PBB): Design a controlled experiment to test how fruit flies respond to environmental cues. The review focuses on behavior, fitness, choice chambers, expected vs. observed results, and using data to support a claim.
- [Lab 13: Enzyme Activity](/ap-bio/required-labs/enzyme-activity/study-guide/j0GgVv64AYM2wt0DlQUH): Measure how enzyme reaction rate changes with conditions such as temperature, pH, substrate concentration, or inhibitors. This guide reviews active sites, denaturation, competitive inhibition, and interpreting rate curves.

## Review Notes

### Lab review: Choosing and sequencing your lab review

Start by identifying which labs connect to the content areas you find hardest. If energy and metabolism are weak spots, prioritize Photosynthesis, Cellular Respiration, and Energy Dynamics. If genetics and evolution feel shaky, work through Bacterial Transformation, Restriction Enzyme Analysis, Hardy-Weinberg, and BLAST. Each lab guide is self-contained, so you can review in any order.

- **Lab guides (13 available)**: Each guide explains the lab's core question, the variables involved, how to read the data, and which AP exam skills it tests. Use them for targeted review, not just pre-lab prep.
- **Score calculator (1 available)**: Use the AP score calculator to estimate your overall AP Biology score as you complete your review. It is not a per-lab tool but helps you track readiness across the full exam.

**Checkpoint:** Before moving on, ask yourself: for each lab, can you state what was measured, what the independent and dependent variables were, and what a result showing no change would mean biologically?

Lab | Core measurement | Key data skill
--- | --- | ---
Diffusion and Osmosis | Percent change in mass, water potential | Quantitative calculation and graph interpretation
Enzyme Activity | Reaction rate under varied conditions | Identifying optimal conditions from rate curves
Cellular Respiration | Oxygen consumption rate | Comparing respiration rates across conditions
Photosynthesis | Rate of photosynthesis via floating leaf disks | Connecting light intensity to reaction rate
Cell Division | Mitotic index from microscope images | Calculating frequency of cells in each stage

## Study Guides

- [Artificial Selection](/ap-bio/required-labs/artificial-selection/study-guide/cyqdArpgong5HkwDVOKG)
- [Mathematical Modeling: Hardy-Weinberg](/ap-bio/required-labs/mathematical-modeling-hardy-weinberg/study-guide/CcqDl5B5cDHDS6gNFbFf)
- [Comparing DNA Sequences to Understand Evolutionary Relationships with BLAST](/ap-bio/required-labs/blast-evolutionary-relationships/study-guide/MiDP8CtCAAYNQW3GMFFc)
- [Diffusion and Osmosis](/ap-bio/required-labs/diffusion-and-osmosis/study-guide/451ICyd52ERQXgqDF7Gs)
- [Photosynthesis](/ap-bio/required-labs/photosynthesis/study-guide/FmbGOzpHyNvOVnobkMKF)
- [Cellular Respiration](/ap-bio/required-labs/cellular-respiration/study-guide/HpNsD38c4CNHRJw7pIKr)
- [Cell Division: Mitosis and Meiosis](/ap-bio/required-labs/cell-division-mitosis-and-meiosis/study-guide/sDu1xUpEGLBh4b1jHo7B)
- [Biotechnology: Bacterial Transformation](/ap-bio/required-labs/bacterial-transformation/study-guide/JtXuo2FXIYgYuM3x3fji)
- [Biotechnology: Restriction Enzyme Analysis of DNA](/ap-bio/required-labs/restriction-enzyme-analysis-of-dna/study-guide/Lao7by8PdZl2yD3nlSd0)
- [Energy Dynamics](/ap-bio/required-labs/energy-dynamics/study-guide/wq1NFweZrh5EpuAHEF9u)
- [Transpiration](/ap-bio/required-labs/transpiration/study-guide/Vf2CqCP0Uy63c0MJoDc3)
- [Fruit Fly Behavior](/ap-bio/required-labs/fruit-fly-behavior/study-guide/t4XYRnAN2gY45Gw58PBB)
- [Enzyme Activity](/ap-bio/required-labs/enzyme-activity/study-guide/j0GgVv64AYM2wt0DlQUH)

## Common Mistakes

- **Confusing transformation efficiency with transformation success**: Transformation efficiency is a calculated rate: colonies per microgram of DNA. Students often describe a plate with many colonies as simply successful without calculating or comparing rates. The AP exam expects you to use the number, not just describe the outcome.
- **Misreading Hardy-Weinberg as a description of evolution**: Hardy-Weinberg describes a population that is not evolving. Students frequently use it to explain how evolution works, when its actual purpose is to serve as a null hypothesis. A deviation from Hardy-Weinberg frequencies is what signals that evolution is occurring.
- **Treating osmosis as movement of solute rather than water**: Water moves from low solute concentration to high solute concentration. Students often reverse this, especially when working with water potential equations. In the osmosis lab, mass increases when water enters the bag, meaning the bag solution had higher solute concentration than the surrounding solution.
- **Describing enzyme denaturation as the enzyme slowing down**: Above the optimal temperature, enzymes do not just slow down. They denature, meaning the active site changes shape permanently and the enzyme cannot function. This distinction matters on the AP exam because it affects whether activity can be restored by returning to optimal conditions.
- **Confusing the BLAST lab with a genetics lab**: BLAST is an evolutionary and phylogenetic tool, not a genetics tool. Students sometimes describe BLAST results in terms of gene function when the lab is actually about using sequence similarity to infer common ancestry and build phylogenetic trees.

## Exam Connections

- **Free-response questions use lab scenarios directly**: AP Biology free-response questions frequently present a modified version of a required lab and ask you to analyze data, identify a flaw in the experimental design, or predict what would happen if a variable changed. Knowing the logic of each required lab, not just the procedure, is what lets you answer these questions under time pressure.
- **Multiple-choice questions test data interpretation across lab types**: Multiple-choice questions often show a graph, table, or gel image drawn from a required lab context and ask you to draw a conclusion or identify the best explanation for a result. The labs most commonly represented include osmosis, enzyme activity, photosynthesis, cellular respiration, and Hardy-Weinberg modeling.
- **Science practices are assessed through lab contexts**: The AP Biology exam assesses science practices including designing controlled experiments, analyzing quantitative data, and constructing explanations from evidence. The required labs are the primary context in which these practices are tested, so reviewing the labs is also reviewing the exam's core skill set.

## Final Review Checklist

- **Identify the independent and dependent variable for each lab**: For every required lab, you should be able to state exactly what was manipulated, what was measured, and what was held constant. This is the foundation for answering any experimental design question on the AP exam.
- **Practice reading and interpreting each lab's data format**: Each lab produces a specific type of data: rate curves for enzyme activity and respiration, percent mass change for osmosis, colony counts for transformation, gel band patterns for restriction analysis, and frequency distributions for Hardy-Weinberg. Make sure you can read each format without hesitation.
- **Connect each lab result to a broader biological principle**: The AP exam rarely asks what you did in a lab. It asks what the result means. Practice explaining how a transformation efficiency result connects to gene expression, or how a deviation from Hardy-Weinberg frequencies indicates that one of the five conditions for equilibrium is not being met.
- **Know what a negative or null result means in each lab**: What does it mean if no colonies grow on the transformation plate? What does it mean if leaf disks do not float in the photosynthesis lab? What does it mean if allele frequencies match Hardy-Weinberg predictions? Being able to interpret null or unexpected results is a high-value AP exam skill.
- **Review the math-based labs with numbers, not just words**: Hardy-Weinberg, osmosis water potential, mitotic index, transformation efficiency, and ecological efficiency all require calculation. Work through at least one numerical example for each before the exam so the formulas feel automatic.
- **Use the score calculator to check your overall readiness**: After completing your lab review, use the AP score calculator available on this page to estimate where you stand across the full exam. Labs connect to multiple units, so strong lab knowledge should lift your score across several content areas.

## Study Plan

- **Day 1: Cellular and molecular labs**: Read the lab guides for Diffusion and Osmosis, Enzyme Activity, Cellular Respiration, and Photosynthesis. For each one, write down the variable being measured, the expected result, and one way the AP exam could present the data. Focus on rate calculations and graph interpretation.
- **Day 2: Cell division and biotechnology labs**: Work through Cell Division, Bacterial Transformation, and Restriction Enzyme Analysis. Practice calculating mitotic index and transformation efficiency with actual numbers. Sketch a sample gel and practice reading fragment sizes to build a restriction map.
- **Day 3: Evolution and population genetics labs**: Review Hardy-Weinberg, BLAST, and Artificial Selection. Work through at least two Hardy-Weinberg problems from start to finish. Practice reading a phylogenetic tree built from BLAST data and explaining what branch length or shared nodes mean for evolutionary relationships.
- **Day 4: Ecology and behavior labs**: Review Energy Dynamics and Fruit Fly Behavior. Calculate ecological efficiency for a sample food chain. Practice setting up a chi-square table for a behavioral experiment and interpreting whether the result is statistically significant.
- **Day 5: Cross-lab connections and score check**: Review how labs connect across units. Photosynthesis and Cellular Respiration both connect to the carbon cycle. Bacterial Transformation and Restriction Enzyme Analysis both connect to gene expression. Hardy-Weinberg and BLAST both connect to natural selection. Use the score calculator to estimate your readiness and identify any remaining gaps.

## More Ways To Review

- [Topic study guides](/ap-bio/required-labs#topics)
- [FRQ practice](/ap-bio/frq-practice)
- [Cheatsheets](/ap-bio/cheatsheets/required-labs)