Biology - CLEP Test Prep


Science is the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.

Biology is the study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behavior, origin, and distribution.

Covering material that is taught in a one-year general biology course, the Biology CLEP exam draws from the three major areas of biological studies:  molecular & cellular biology, organismal biology and population biology.

The Biology CLEP exam contains approximately 115 multiple choice questions to be answered in 90 minutes.  Some of these are pretest questions that will not be scored. The College Board provides the parameters for the exam which are listed below.


  • Knowledge of the facts, principles, and processes of biology
  • Knowledge of the basic scientific process:  how information is collected, how it is interpreted, how to develop hypotheses from known information, how study leads to conclusions, and how to make further predictions
  • Scientific study is a human undertaking with social consequences

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


This branch of biology studies how molecules control all processes and growth of the cell, the basic unit of life.

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 (bacteria, plant and animal)


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

Energy transformations: 

  • Glycolysis, cellular 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% of the exam

The study of the structure, function, ecology and evolution at the level of the organism; an individual form of life such as a bacterium, plant or animal.

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 generation cycles in ferns, conifers and Angiosperms
  • Gamete formation and fertilization
  • Growth and development: hormonal control
  • Tropisms and photoperiodicity

Structure and function in animals with emphasis on vertebrates:

  • Major systems ( 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 patterns (dominance, segregation, independent assortment)
  • Chromosomal basis of inheritance
  • Linkage, including sex-linked traits (hemophilia, colorblindness)
  • Polygenic inheritance (height, weight, skin color)

POPULATION BIOLOGY—33% of the exam

The study of a group of individuals of the same species that have a high probability of interacting with each other; especially the growth and regulation of the population size, genetics, demography and life history evolution of the population.

Principles of ecology:

  • Energy flow and productivity in ecosystems
  • Biogeochemical cycles (water, nitrogen, carbon)
  • 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 (taxonomy)
  • Evolutionary history of humans

Principles of behavior:

  • Stereotyped, learned social behavior
  • Societies (emphasis on 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)

Each college sets their own credit-granting policies for the exam, so check with your college admissions office, test center, or academic adviser before taking the test.