Lesson 10.4: Background Science Knowledge

Introduction

In this lesson, we will explore the limited background science knowledge that may appear on the ACT Science section, particularly in the domains of biology, chemistry, physics, and earth and space science. Unlike traditional science exams that often focus on memorization, the ACT emphasizes scientific reasoning skills. This means that while some basic scientific knowledge is beneficial, it is crucial to understand how to interpret and analyze data even when you lack extensive background information.

Learning Objectives

1. Understand the limited outside knowledge that can appear in biology, chemistry, physics, and earth and space science.
2. Recognize when a question requires prior knowledge versus when it can be answered using only the passage provided.
3. Apply core science facts when a question requires outside knowledge.
4. Distinguish passage-only questions from those needing background knowledge.
5. Explain the main ideas and terminology relevant to Lesson 10.4: Background Science Knowledge.

Understanding Scientific Fields

Biology

Biology is the study of living organisms, and it covers a wide range of topics including cell structure, genetics, evolution, and ecosystems. On the ACT, a few key biological concepts may appear that students should be familiar with:

• Cell Structure: Understanding the basic components of a cell (nucleus, mitochondria, etc.) and their functions.
• Genetics: Familiarity with concepts such as DNA, genes, and basic inheritance patterns (like dominant and recessive traits).

Worked Example

Imagine a question presents a passage about a genetic study involving fruit flies. It describes a trait that is inherited, and you are asked to predict the possible genotype of the offspring. Knowing that dominant traits mask recessive ones, you can apply basic genetics principles. If the trait is dominant and the parental genotypes are known, use a Punnett square to determine possible offspring genotypes.

Chemistry

Chemistry involves understanding the properties and changes of matter, including concepts such as chemical reactions, the periodic table, acids and bases, and stoichiometry. For the ACT, grasping some fundamental concepts is essential:

• Chemical Reactions: Recognizing reactants and products, understanding balancing equations.
• Periodic Table: Knowing the symbols and common characteristics of elements.

Worked Example

Consider a problem that shows an unbalanced chemical equation:

$$ \text{H}_2 + \text{O}_2

ightarrow $\text{H}_2$$\text{O}$ $$

To balance this equation, we need to ensure there are equal numbers of each type of atom on both sides. The balanced equation is:

$$ 2 \text{H}_2 + \text{O}_2

ightarrow $2 \text{H}_2$$\text{O}$ $$

It can help you quickly answer questions about what happens during the reaction.

Physics

Physics focuses on the laws governing matter and energy. Key topics include forces, motion, energy, and waves. On the ACT, you might encounter questions covering:

• Newton's Laws: Understanding how they predict motion and forces.
• Energy Forms and Conservation: Familiarizing yourself with kinetic, potential energy, and the conservation of mass-energy principle.

Worked Example

If you have a question about a ball being thrown in the air, it may ask you to identify the types of energy present at different points in its path. At the highest point, its potential energy is maximized, while its kinetic energy is minimized. Recognizing these concepts can help you answer questions regarding energy transformations.

Earth and Space Science

This field encompasses topics such as geology, meteorology, astronomy, and environmental science. Knowledge of basic Earth systems and cosmic phenomena can be beneficial. Key areas to focus on include:

• Rock Cycle: Knowing the stages of rock formation and transformation.
• Weather Patterns: Understanding how meteorological data (like temperature and precipitation) is interpreted.

Worked Example

Suppose a passage discusses changes in climate and presents a graph of average global temperatures over several decades. You may be asked to infer the implications of temperature rises. Recognizing the connection between temperature and potential impacts on ecosystems (like melting glaciers) will assist you in answering such questions accurately.

Distinguishing Between Passage-Only and Knowledge-Based Questions

A critical skill for success in the ACT Science section is determining whether you can solve a question using information from the passage or if you need outside knowledge. Here are some tips for recognizing each type:

Passage-Only Questions

• Typically provide all the necessary data within the passage.
• May include graphs, tables, or descriptions sufficient for reasoning through the problem.
• Look for wording like “according to the passage” or “based on the information given.”

Example

If a passage includes a chart comparing growth rates of two species of plants under varying light conditions, a question might ask which plant thrived in the most light. Since you can refer directly to the chart data, this is a passage-only question.

Background Knowledge Questions

• Require specific scientific concepts that are not articulated in the passage.
• These may involve foundational science principles or definitions necessary to interpret the data.
• Phrasing might indicate a need for external knowledge (e.g., “What is the definition of…”).

Example

If a question asks about the process of photosynthesis and your passage contains information about plant growth but does not describe photosynthesis, then you need background knowledge to answer it correctly.

Conclusion

Understanding the limited background science knowledge required for the ACT Science section can enhance your performance. Familiarizing yourself with core concepts in biology, chemistry, physics, and earth and space science can allow you to differentiate between the use of provided data in passages and knowledge you must apply outside of what is given. Use worked examples throughout this lesson to reinforce this understanding, and practice identifying type questions as you prepare for the ACT.

Study Notes

• The ACT Science section tests reasoning over memorization.
• Key biological concepts may include cell structure and genetic inheritance.
• Chemistry principles essential for the ACT include balancing reactions and periodic table knowledge.
• Physics revolves around understanding motion, forces, and energy transformations.
• Earth and Space Science includes topics such as the rock cycle and weather patterns.
• Practice distinguishing between passage-only questions and those requiring background knowledge.