The test consists of approximately 200 five-choice questions, a number of which are grouped in sets toward the end of the test and are based on descriptions of laboratory and field situations, diagrams, or experimental results.
The content of the test is organized into three major areas: cellular and molecular biology, organismal biology, and ecology and evolution. Approximately equal weight is given to each of these three areas. In addition to the total score, a sub score in each of these subfield areas is reported. Subject area subdivisions indicated by Arabic numerals may not contain equal numbers of questions.
The approximate distribution of questions by content category is shown below.
Fundamentals of cellular biology, genetics, and molecular biology are addressed.
Major topics in cellular structure and function include metabolic pathways and their regulation, membrane dynamics, cell surfaces, organelles, cytoskeleton, and cell cycle.
Major areas in genetics and molecular biology include chromatin and chromosomal structure, genomic organization and maintenance, and the regulation of gene expression.
The cellular basis of immunity, the mechanisms of antigen-antibody interactions, and cell-pathogen interactions are included.
Distinctions between prokaryotic and eukaryotic cells are considered where appropriate.
Attention is also given to experimental methodology.
Biological compounds
Macromolecular structure and bonding
Abiotic origin of biological molecules
Enzyme activity, receptor binding, and regulation
Major metabolic pathways and regulation
Respiration, fermentation, and photosynthesis
Synthesis and degradation of macromolecules
Hormonal control and intracellular messengers
Membrane dynamics and cell surfaces
Transport, endocytosis, and exocytosis
Electrical potentials and neurotransmitters
Mechanisms of cell recognition, cell junctions, and plasmodesmata
Cell wall and extracellular matrix
Organelles: structure, function, and targeting
Cytoskeleton, motility, and shape
Actin-based systems
Microtubule-based systems
Intermediate filaments
Bacterial flagella and movement
Cell cycle, growth, division, and regulation
Genetic foundations
Mendelian inheritance; Pedigree analysis
Prokaryotic genetics (transformation, transduction, and conjugation)
Genetic mapping
Chromatin and chromosomes
Nucleosomes
Karyotypes
Chromosomal aberrations
Polytene chromosomes
Genome sequence organization
Introns and exons; Single-copy and repetitive DNA
Transposable elements
Genome maintenance
DNA replication; DNA mutation and repair
Gene expression and regulation in prokaryotes and eukaryotes: mechanisms
The operon; Promoters and enhancers; Transcription factors; RNA and protein synthesis; Processing and modifications of both RNA and protein
Gene expression and regulation: effects
Control of normal development; Cancer and oncogenes
Signaling mechanisms in cells
Immunobiology
Cellular basis of immunity; Antibody diversity and synthesis
Antigen-antibody interactions
Bacteriophages, animal viruses, and plant viruses
Viral genomes, replication, and assembly
Virus-host cell interactions
Recombinant DNA methodology
Restriction endonucleases; Blotting and hybridization
Restriction fragment length polymorphisms;
DNA cloning, sequencing, and analysis;
Polymerase chain reaction
The structure, physiology, behavior, and development of plants and animals are addressed.
Topics covered include nutrient procurement and processing, gas exchange, internal transport, regulation of fluids, control mechanisms and effectors, and reproduction in autotrophic and heterotrophic organisms.
Examples of developmental phenomena range from fertilization through differentiation and morphogenesis.
Perceptions and responses to environmental stimuli are examined as they pertain to both plants and animals.
Major distinguishing characteristics and phylogenetic relationships of selected groups from the various kingdoms are also covered.
Exchange with environment
Nutrient, salt, and water exchange
Gas exchange; Energy
Internal transport and exchange
Circulatory, gastrovascular, and digestive systems
Support and movement
Support systems (external, internal, and hydrostatic)
Movement systems (flagellar, ciliary, and muscular)
Integration and control mechanisms
Nervous and endocrine systems
Behavior (communication, orientation, learning, and instinct)
Metabolic rates (temperature, body size, and activity)
Reproductive structures
Meiosis, gametogenesis, and fertilization
Early development (e.g., polarity, cleavage, and gastrulation)
Developmental processes (e.g., induction, determination, differentiation, morphogenesis, and metamorphosis)
External control mechanisms (e.g., photoperiod)
Tissues, tissue systems, and organs
Water transport, including absorption and transpiration
Phloem transport and storage
Mineral nutrition
Plant energetics (e.g., respiration and photosynthesis)
Reproductive structures
Meiosis and sporogenesis
Gametogenesis and fertilization
Embryogeny and seed development
Meristems, growth, morphogenesis, and differentiation
Control mechanisms (e.g., hormones, photoperiod, and tropisms)
Archaebacteria Morphology, physiology, and identification
Eubacteria (including cyanobacteria)
Morphology, physiology, pathology, and identification
Protista
Protozoa, other heterotrophic Protista (slime molds and Oomycota), and autotrophic Protista
Major distinguishing characteristics
Phylogenetic relationships
Importance (e.g., eutrophication, disease)
Fungi
Distinctive features of major phyla (vegetative, asexual, and sexual reproduction)
Generalized life cycles
Importance (e.g., decomposition, biodegradation, antibiotics, and pathogenicity)
Lichens
Animalia with emphasis on major phyla
Major distinguishing characteristics
Phylogenetic relationships
Plantae with emphasis on major phyla
Alternation of generations
Major distinguishing characteristics
Phylogenetic relationships
Interactions of organisms and their environment, emphasizing biological principles at levels above the individual.
Ecological and evolutionary topics are given equal weight.
Ecological questions range from physiological adaptations to the functioning of ecosystems.
Although principles are emphasized, some questions may consider applications to current environmental problems.
Questions in evolution range from its genetic foundations through evolutionary processes to their consequences.
Evolution is considered at the molecular, individual, population, and higher levels.
Principles of ecology, genetics, and evolution are interrelated in many questions.
Some questions may require quantitative skills, including the interpretation of simple mathematical models.
Environment/organism interaction
Biogeographic patterns; Adaptations to environment; Temporal patterns
Behavioral Ecology
Habitat selection; Mating systems; Social systems; Resource acquisition
Population structure and function
Population dynamics/regulation; Demography and life history strategies
Communities
Interspecific relationships; Community structure and diversity; Change and succession
Ecosystems
Productivity and energy flow; Chemical cycling
Genetic variability
Origins (mutations, linkage, recombination, and chromosomal alterations)
Levels (e.g., polymorphism and heritability)
Spatial patterns (e.g., clines and ecotypes)
Hardy-Weinberg equilibrium
Evolutionary processes
Gene flow and genetic drift; Natural selection; Levels of selection (e.g., individual and group)
Evolutionary consequences
Fitness and adaptation; Speciation; Systematics and phylogeny; Convergence, divergence, and extinction
History of life
Origin of prokaryotic and eukaryotic cells
Fossil record
Paleontology and paleoecology