Must Know About AP Biology Labs
AP Biology labs are an essential part of the curriculum that help bridge theory with hands-on experience. These labs make up about 25% of your class time and serve as the backbone for connecting course concepts to real-world applications. Many AP exam questions are directly related to these lab experiments, often involving data analysis or experimental interpretation.
This guide will walk you through the key AP Biology labs, offering insights into what you should know to ace this section, along with recommended virtual simulations for additional practice.
Key Lab Skills to Master:
Make observations, collect data, construct proper graphs, and evaluate data collected.
Review and understand lab conclusions.
Answer “what if” questions to demonstrate deep understanding, such as “What would happen if…” or “What could be the next step in this investigation?”
Perform calculations based on lab data.
Write predictions and hypotheses, identifying independent and dependent variables.
Identify and justify appropriate experimental controls.
Let’s break down the labs you need to know, unit by unit.
Unit 1: Chemistry of Life
There are no College Board-recommended labs specifically for this unit. However, mastering the foundational chemistry concepts—like properties of water, elements, molecules, and macromolecules—is crucial for understanding the rest of the course.
Key Concepts to Review:
The four macromolecules: Carbohydrates, Proteins, Lipids, Nucleic Acids.
Properties of water: polarity, cohesion, adhesion, and specific heat.
Common Practice:
Pattern Matching Activity for reviewing macromolecules.
Water Molecule Model Building to visualize water’s properties.
Unit 2: Cell Structure and Function
Diffusion and Osmosis Lab is a major part of this unit, divided into three parts:
Surface Area to Volume Ratio: Agar cubes of different sizes are immersed in an acid solution. As surface area-to-volume ratios decrease, diffusion efficiency drops. This highlights the limits of cell size due to nutrient absorption constraints.
Dialysis Tubing Experiment: Dialysis bags are used as models of living cells to study osmosis. You observe mass changes as different concentrations of sugar are placed in distilled water. This demonstrates how water moves from areas of high water potential to low water potential.
Potato Osmosis: Potato cores are submerged in varying solute concentrations (e.g., salt or sugar). By measuring mass changes, students see how water moves across semi-permeable membranes in plant cells.
Key Points:
Water moves from areas of high water potential (low solute) to low water potential (high solute).
Hypertonic, hypotonic, and isotonic solutions affect cell mass differently.
Virtual Labs:
Biomembranes I: Membrane Structure and Transport
Diffusion and Surface Area/Volume Simulation by Jon Darkow
Unit 3: Cellular Energetics
This unit dives into how organisms capture and utilize energy. There are three core labs:
Enzyme Catalysis: Enzymes are proteins that catalyze biological reactions. In this lab, catalase (which breaks down hydrogen peroxide) is used to show how different factors—substrate concentration, temperature, or pH—influence enzymatic activity.
Photosynthesis (Floating Leaf Disc Assay): Discs punched out from spinach leaves are submerged in a solution. The time it takes for them to float measures the rate of photosynthesis under different conditions (light intensity, color, CO2 concentration).
Cellular Respiration: This lab uses respirometers to measure the rate of respiration in germinating versus non-germinating seeds. You’ll observe how oxygen consumption changes under different conditions.
Virtual Labs:
Photosynthesis Simulation by Jon Darkow
Cell Respiration Multiple Dose Model Simulation by Jon Darkow
Unit 4: Cell Communication and Cell Cycle
This unit covers how cells communicate and replicate.
Mitosis and Meiosis Lab: A common lab involves onion root tips treated with different chemicals to observe mitotic stages. By analyzing cells under a microscope, you’ll quantify cells in different phases of mitosis (interphase, prophase, metaphase, etc.). This lab demonstrates how external factors can influence cell growth and division.
Key Concepts:
Signal Transduction Pathways: Understanding how cells respond to external stimuli is critical in understanding cell regulation.
Virtual Tools:
Cell Cycle Simulation by Jon Darkow
Insulin Secretion and Membrane Transport Simulation
Unit 5: Heredity
This unit dives deep into how traits are passed on through generations.
Mendelian and Non-Mendelian Genetics Labs:
Drosophila Fly Crosses: Using virtual labs to conduct genetic crosses, students observe different inheritance patterns—such as Mendelian dominance, incomplete dominance, and codominance. Non-Mendelian inheritance is also explored through traits like polygenic inheritance (e.g., human height).
Meiosis Lab: Onion root tip experiments are used to examine meiosis. You’ll see the importance of meiosis for genetic diversity, which is key for natural selection and evolution.
Virtual Labs:
Virtual Fly Lab for Genetics Cross Practice
Drosophila Apterous vs. Wild-type Simulation
Unit 6: Gene Expression and Regulation
Gene regulation is a cornerstone of understanding how traits manifest.
Gene Transformation and Gel Electrophoresis Lab:
In this experiment, students insert a gene of interest into bacteria using a plasmid. This genetic transformation enables the bacteria to express new traits, such as antibiotic resistance or fluorescence.
Gel Electrophoresis is used to separate DNA fragments by size, a technique often employed in forensic analysis and genetic engineering.
Key Concepts:
Central Dogma of molecular biology: DNA → RNA → Protein.
Gene Splicing and Regulation: Understanding how introns are removed and exons expressed.
Virtual Resources:
Lac Operon with Diauxic Simulation
Regulation of the Lactase Gene Click and Learn
Unit 7: Natural Selection and Evolution
Evolution is at the core of biological science.
Hardy-Weinberg Equilibrium Lab: This lab explores allele frequency in non-evolving populations, providing insight into how populations change over time and the conditions needed for genetic equilibrium.
Artificial Selection Lab: Students select for a trait in Wisconsin Fast Plants to study selection pressures. This lab provides hands-on experience with observing generational changes under selective breeding.
BLAST and Phylogenetic Tree Labs: Using online tools to compare DNA sequences, you’ll create phylogenetic trees that highlight the evolutionary relationships between species.
Key Concepts:
Mechanisms of evolutionary change: mutation, migration, natural selection, and genetic drift.
Artificial vs. Natural Selection: The power of selective breeding versus natural adaptive processes.
Virtual Labs:
Guppy Evolution Simulation
Creating Phylogenetic Trees Click and Learn
Unit 8: Ecology
This unit ties together all the major themes in biology, emphasizing interactions within and among species.
Energy Dynamics Lab: This lab measures the flow of energy through an ecosystem. Using Wisconsin Fast Plants and cabbage white butterflies, you’ll estimate net primary productivity and understand the importance of producers and consumers.
Transpiration Lab: Explore how environmental factors like light, humidity, and wind affect transpiration rates in plants. This lab demonstrates the significance of transpiration for nutrient movement within plants and overall ecosystem water cycles.
Animal Behavior Lab: Using pillbugs, students set up choice chambers to study environmental preferences (e.g., light versus dark, wet versus dry). You’ll see how organisms adapt to maximize survival and resource use.
Key Tools:
Simpson Diversity Index for measuring species diversity in ecosystems.
Population Growth Models to understand logistic and exponential growth patterns.
Virtual Labs:
Transpiration Simulation using Photometers
Animal Behavior Simulation by Jon Darkow
Final Thoughts
AP Biology labs are designed to give you hands-on experience with the scientific method and connect the broader concepts of biology to experiments that reveal how living organisms interact with each other and their environments. Practicing with virtual simulations and understanding the core concepts behind these labs will set you up for success in the AP exam and beyond.
Remember, success in AP Biology is about making connections—between concepts, data, and real-life applications. These labs help you put theory into practice, and in doing so, bring biology to life!
