Biology 2018-02-06T01:40:22+00:00


The Biology CLEP exam covers material that is usually taught in a one-year college general biology course. The subject matter tested covers the broad field of the biological sciences, organized into three major areas: molecular and cellular biology, organismal biology, and population biology.

The examination contains approximately 115 questions to be answered in 90 minutes.

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Knowledge and Skills Required

Questions on the Biology exam require test takers to demonstrate one or more of the following abilities.

  • Knowledge of facts, principles, and processes of biology
  • Understanding the means by which information is collected, how it is interpreted, how one hypothesizes from available information, and how one draws conclusions and makes further predictions
  • Understanding that science is a human endeavor with social consequences

Exam Breakdown

The subject matter of the Biology exam is drawn from the following topics. The percentages next to the main topics indicate the approximate percentage of exam questions on that topic.

Molecular and Cellular Biology (33%)

Chemical composition of organisms

  • Simple chemical reactions and bonds
  • Properties of water
  • Chemical structure of carbohydrates, lipids, proteins, nucleic acids
  • Origin of life


  • Structure and function of cell organelles
  • Properties of cell membranes
  • Comparison of prokaryotic and eukaryotic cells


  • Enzyme-substrate complex
  • Roles of coenzymes
  • Inorganic cofactors
  • Inhibition and regulation

Energy transformations

  • Glycolysis, respiration, anaerobic pathways
  • Photosynthesis

Cell division

  • Structure of chromosomes
  • Mitosis, meiosis, and cytokinesis in plants and animals

Chemical nature of the gene

  • Watson-Crick model of nucleic acids
  • DNA replication
  • Mutations
  • Control of protein synthesis: transcription, translation, posttranscriptional processing
  • Structural and regulatory genes
  • Transformation
  • Viruses

Organismal Biology (34%)

Structure and function in plants with emphasis on angiosperms

  • Root, stem, leaf, flower, seed, fruit
  • Water and mineral absorption and transport
  • Food translocation and storage

Plant reproduction and development

  • Alternation of generations in ferns, conifers, and flowering plants
  • Gamete formation and fertilization
  • Growth and development: hormonal control
  • Tropisms and photoperiodicity

Structure and function in animals with emphasis on vertebrates

  • Major systems (e.g., digestive, gas exchange, skeletal, nervous, circulatory, excretory, immune)
  • Homeostatic mechanisms
  • Hormonal control in homeostasis and reproduction

Animal reproduction and development

  • Gamete formation, fertilization
  • Cleavage, gastrulation, germ layer formation, differentiation of organ systems
  • Experimental analysis of vertebrate development
  • Extraembryonic membranes of vertebrates
  • Formation and function of the mammalian placenta
  • Blood circulation in the human embryo

Principles of heredity

  • Mendelian inheritance (dominance, segregation, independent assortment)
  • Chromosomal basis of inheritance
  • Linkage, including sex-linked
  • Polygenic inheritance (height, skin color)
  • Multiple alleles (human blood groups)

Population Biology (33%)

Principles of ecology

  • Energy flow and productivity in ecosystems
  • Biogeochemical cycles
  • Population growth and regulation (natality, mortality, competition, migration, density, r- and K-selection)
  • Community structure, growth, regulation (major biomes and succession)
  • Habitat (biotic and abiotic factors)
  • Concept of niche
  • Island biogeography
  • Evolutionary ecology (life history strategies, altruism, kin selection)

Principles of evolution

  • History of evolutionary concepts
  • Concepts of natural selection (differential reproduction, mutation, Hardy-Weinberg equilibrium, speciation, punctuated equilibrium)
  • Adaptive radiation
  • Major features of plant and animal evolution
  • Concepts of homology and analogy
  • Convergence, extinction, balanced polymorphism, genetic drift
  • Classification of living organisms
  • Evolutionary history of humans

Principles of behavior

  • Stereotyped, learned social behavior
  • Societies (insects, birds, primates)

Social biology

  • Human population growth (age composition, birth and fertility rates, theory of demographic transition)
  • Human intervention in the natural world (management of resources, environmental pollution)
  • Biomedical progress (control of human reproduction, genetic engineering)
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User Test Results for the Biology CLEP Exam

292 users have submitted their test results to us since March 2016

274 (93.8%) of those users have reported an ACE recommended passing score

The table below represents our users most recent test results for the Biology CLEP exam after using Credits4Less.

Note: The date shown below represents the date that they reported their score to us.

Feb 21, 2018Pass61
Feb 11, 2018Pass53
Feb 8, 2018Pass76
Feb 1, 2018Pass78
Jan 25, 2018Pass68

Our Study Guide

Credits4Less’ Biology study guide will leave you fully prepared to pass your Biology CLEP exam. Our study guide is broken down to match the exact make up of the actual CLEP exam with each unit containing a set of cheat sheet notes and dozens of practice questions.

1. Study guides that match the actual exam’s breakdown

2. Units that contain cheat sheet notes and practice questions

3. Hundreds of practice questions

4. Review your answers and learn from your mistakes

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