# Reading Biology Data Tables and Graphs
The ACT Science section frequently includes biology-related passages with data presented in tables, graphs, and figures. You don't need to memorise biology facts — the key is quickly and accurately extracting information from the data provided.
1. Types of Biology Data Representations
Tables
- Rows often represent different organisms, time points, or experimental conditions
- Columns represent measured variables (population size, growth rate, concentration, etc.)
- Always read column headers and units carefully
Example Table: Bacterial Growth at Different Temperatures
| Temperature (°C) | Colony Count (×10³) at 24h | Colony Count (×10³) at 48h |
|---|---|---|
| 20 | 12 | 45 |
| 30 | 35 | 120 |
| 37 | 58 | 210 |
| 45 | 22 | 65 |
Graphs
- Line graphs: Show trends over time (e.g., population growth curves, enzyme activity vs. temperature)
- Bar graphs: Compare quantities across categories (e.g., species richness in different habitats)
- Scatter plots: Show relationships between two variables (e.g., body mass vs. metabolic rate)
Diagrams
- Cell diagrams with labelled organelles
- Food webs and ecological pyramids
- Pedigree charts and genetic crosses
2. Key Skills for Biology Data Questions
Reading Values
- Locate the correct row/column or point on a graph
- Interpolate between data points when needed
- Pay attention to scientific notation (e.g., ×10³)
Identifying Trends
- Is the relationship direct (both increase) or inverse (one increases, the other decreases)?
- Is growth linear or exponential?
- Where are the maxima and minima?
Making Comparisons
- Compare values across conditions or groups
- Calculate differences or ratios when asked
- Identify the condition that produces the greatest/least effect
3. Worked Example
Question: Based on the table above, at which temperature did the bacteria show the highest growth rate between 24h and 48h?
Solution:
- Calculate increase for each temperature:
- 20°C: \(45 - 12 = 33\) thousand
- 30°C: \(120 - 35 = 85\) thousand
- 37°C: \(210 - 58 = 152\) thousand
- 45°C: \(65 - 22 = 43\) thousand
- Answer: 37°C showed the greatest increase in colony count.
4. Practice Questions
Q1. A graph shows the dissolved oxygen concentration in a pond over 24 hours. The oxygen level is highest at 4 PM and lowest at 4 AM. What process most likely explains this pattern?
A1. Photosynthesis by aquatic plants produces oxygen during daylight hours. At night, only respiration occurs, consuming oxygen. Peak oxygen occurs in late afternoon after hours of photosynthesis.
Q2. A table shows that Plant A grew 15 cm in high light and 5 cm in low light, while Plant B grew 12 cm in both conditions. Which plant is more affected by light intensity?
A2. Plant A — it shows a 10 cm difference between conditions, while Plant B shows no difference, suggesting Plant B is less dependent on light intensity for growth.
Want to check your answers and get step-by-step solutions?
Summary
- Always read titles, labels, and units before analysing data
- Identify the type of representation and what variables are shown
- Look for trends, patterns, and outliers
- Practice extracting specific values quickly — speed matters on the ACT