Skip to main content



1. About this Course

It covers the fundamentals taught in introductory courses surveying both biological and physical sciences at the freshman or sophomore level at college. Such courses generally satisfy distribution or general education requirements in science that usually are not required of nor taken by science majors.

"We will cover a wide variety of topics in this course. I will draw your attention to some of the interesting history and real-world applications of the material at certain points. Many of the topics, such as evolution, genetics, chemistry, and physics have rich and storied histories," explains our instructor Dr. Amy Nielsen.

"Mastering the topics presented in this course will allow you to transition to more sophisticated coursework in both biological and physical sciences. This course forms a foundation from which you can begin to achieve your educational goals." 

The Natural Sciences course –completely self-paced and entirely free– is organized into ten topical chapters or modules that contain short video lessons, exercises, readings and other interactive resources. 

The goal of the creator of this course –Modern States Education Alliance, a non-profit organization– is to prepare you to pass the College Board's CLEP examination and obtain college credit for free.

2. About the Exam 

The Natural Sciences CLEP examination contains approximately 120 questions to be answered in 90 minutes. 

It is intended to test the understanding of scientific concepts that an adult with a liberal arts education should have, but it not intended for those specializing in science. It does not stress the retention of factual details; rather, it emphasizes the knowledge and application of the basic principles and concepts of science, the comprehension of scientific information, and the understanding of issues of science in contemporary society.

The primary objective of the examination is to give candidates the opportunity to demonstrate a level of knowledge and understanding expected of college students meeting a distribution or general education requirement in the natural sciences.

Note: An institution may grant college credit toward fulfillment of such a requirement for satisfactory scores on the exam. Some may grant specific course credit, on the basis of the total score for a two-semester survey course covering both biological and physical sciences.  

3. Required Knowledge

The CLEP exam requires you to demonstrate one or more of the following abilities in the following proportions:

  • Knowledge of fundamental facts, concepts, and principles (about 40% of the examination) 

  • Interpretation and comprehension of information (about 20% of the examination) presented in the form of graphs, diagrams, tables, equations, or verbal passages.

  • Qualitative and quantitative application of scientific principles (about 40% of the examination), including applications based on material presented in the form of graphs, diagrams, tables, equations, or verbal passages; more emphasis is given to qualitative than quantitative applications. 

The subject matter of the exam is drawn from the following topics

Note the approximate percentage of exam questions on that topic.

•   Biological Science (50%)

  • 10% Origin and evolution of life, classification of organisms
  • 10% Cell organization, cell division, chemical nature of the gene, bioenergetics, biosynthesis
  • 20% Structure, function, and development in organisms; patterns of heredity
  • 10% Concepts of population biology with emphasis on ecology

•   Physical Science (50%)

  • 7% Atomic and nuclear structure and properties, elementary particles, nuclear reactions
  • 10% Chemical elements, compounds and reactions, molecular structure and bonding
  • 12% Heat, thermodynamics, and states of matter; classical mechanics; relativity
  • 4% Electricity and magnetism, waves, light, and sound
  • 7% The universe: galaxies, stars, the solar system
  • 10% The Earth: atmosphere, hydrosphere, structure features, geologic processes, and history


Note: The examination includes some questions that are interdisciplinary and cannot be classified in one of the listed categories. Some of the questions cover topics that overlap with those listed previously, drawing on areas such as history and philosophy of science, scientific methods, science applications and technology, and the relationship of science to contemporary problems of society, such as environmental pollution and depletion of natural resources. Some questions are laboratory oriented.

4. Course Modules

Following is the outline of our course:


Module 1: Evolution and Classification

  1.0 Introduction

  1.1 Origin of Life and Plants

  1.2 Animal Evolution

  1.3 Human Evolution

  1.4 Mechanisms of Evolution

  1.5 Hardy-Weinberg Equilibrium 

  1.6 Mechanisms of Speciation 

  1.7 Classification of Living Organisms


Module 2: Cellular and Molecular Biology

  2.0 Introduction

  2.1 Cell Structure

  2.2 Transport Across Cell Membranes

  2.3 Cellular Metabolism  

  2.4 DNA Replication  

  2.5 Cell Division

  2.6 Biosynthesis


Module 3: Structure, Function, and Genetics of Plants and Animals

  3.0 Introduction 

  3.1 Structure of Plants

  3.2 Plant Physiology and Reproduction

  3.3 Structure and Function of Animal Tissues

  3.4 Anatomy of Animal Systems, Part 1

  3.5 Anatomy of Animal Systems, Part 2

  3.6 Homeostasis, Hormones, and Reproduction

  3.7 Principles of Genetics

  3.8 Modern Genetics and Inheritance


Module 4: Ecology and Population Biology

  4.0 Introduction   

  4.1 Ecology and The Energy Cycle

  4.2 Ecological Cycles

  4.3 Population Growth and Models

  4.4 Population Growth and Limiting Factors

  4.5 Community Structure and Biogeography


Module 5: Atomic Chemistry

  5.0 Introduction   

  5.1 Structure of the Atom

  5.2 The Periodic Table

  5.3 Nuclear Reactions

  5.4 Rate of Decay and Half-Life


Module 6: Reaction Chemistry

  6.0 Introduction  

  6.1 Chemical Elements

  6.2 Chemical Bonding

  6.3 Chemical Reactions

  6.4 Thermodynamics

  6.5 Properties of Water

  6.6 Important Biomolecules


Module 7: Physics

  7.0 Introduction    

  7.1 Heat and Thermodynamics

  7.2 States of Matter, Density, and Gravity

  7.3 Classical Mechanics and Relativity


Module 8: Energy

  8.0 Introduction    

  8.1 Electricity and Circuits

  8.2 Electricity and Magnetism

  8.3 Introduction to Waves

  8.4 Sound and Light Waves

  8.5 Sound Waves and the Doppler Effect


Module 9: The Universe

  9.0 Introduction    

  9.1 The Universe and Solar System

  9.2 Seasons and the Moon


Module 10: The Earth

  10.0 Introduction

  10.1 Earth’s Atmosphere

  10.2 Earth’s Layers

5. About Dr. Amy Nielsen, Washington State University

Dr. Amy Nielsen was born and raised in Rockford Illinois, home to Cheap Trick and the Rockford Peaches. (She was not a part of either group.) She received a double B.S. in Chemistry and Botany from Iowa State University, where she performed research with Nikki Pohl and Walt Trahanovsky.

Following her childhood dream of learning to surf, she went to California, where she also received her Ph.D. in Organic Chemistry, conducting research in solid-state photochemistry under the direction of Miguel Garcia-Garibay at UCLA. She discovered her love of teaching chemistry as a Visiting Assistant Professor at Loyola Marymount University in Los Angeles, and hasn’t looked back ever since.

Amy is now a Clinical Assistant Professor in the Department of Chemistry and Executive Secretary of the Faculty Senate, both at Washington State University. She is also the chair of the local chapter of the American Chemical Society. She does research with the Mancini lab in the field of chemical immunology. Her current projects include the synthesis and testing of rationally designed immunostimulants susceptible to p-glycoprotein efflux from multi-drug resistant cancers.

Her awards include ASWSU Exceptional Professor of the Year (2017) and the Gene and Priscilla Alberts Endowment for Excellence in Chemistry (2016).

6. How CLEP Works

Developed by the College Board, CLEP (College-Level Examination Program®) is the most widely accepted credit-by-examination program.

CLEP’s credits are accepted by 2,900 colleges and universities, according to the College Board. These tests assess college-level knowledge in 33 subject areas.

Modern States Education Alliance is the non-profit organization behind these edX-style courses. Its project is called “Freshman Year for Free” and its mission is to make college more accessible and affordable through free, high-quality online education.

• CLEP® Natural Sciences: at a Glance

• 'Passing the CLEP and Learning with Modern States' orientation course