• 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.

I. Cellular And Molecular Biology - 33-34%

  • 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.

A. Cellular Structure and Function - 16-17%

  1. Biological compounds
    Macromolecular structure and bonding
    Abiotic origin of biological molecules

    Enzyme activity, receptor binding, and regulation

  2. Major metabolic pathways and regulation
    Respiration, fermentation, and photosynthesis
    Synthesis and degradation of macromolecules
    Hormonal control and intracellular messengers

  3. 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

  4. Organelles: structure, function, and targeting

    Cytoskeleton, motility, and shape
    Actin-based systems
    Microtubule-based systems
    Intermediate filaments
    Bacterial flagella and movement

  5. Cell cycle, growth, division, and regulation

B. Genetics and Molecular Biology - 16-17%

  1. Genetic foundations
    Mendelian inheritance; Pedigree analysis
    Prokaryotic genetics (transformation, transduction, and conjugation)
    Genetic mapping

  2. Chromatin and chromosomes
    Chromosomal aberrations
    Polytene chromosomes

  3. Genome sequence organization
    Introns and exons; Single-copy and repetitive DNA
    Transposable elements

  4. Genome maintenance
    DNA replication; DNA mutation and repair

  5. 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

  6. Gene expression and regulation: effects
    Control of normal development; Cancer and oncogenes
    Signaling mechanisms in cells

  7. Immunobiology
    Cellular basis of immunity; Antibody diversity and synthesis
    Antigen-antibody interactions

  8. Bacteriophages, animal viruses, and plant viruses
    Viral genomes, replication, and assembly
    Virus-host cell interactions

  9. Recombinant DNA methodology
    Restriction endonucleases; Blotting and hybridization
    Restriction fragment length polymorphisms;
    DNA cloning, sequencing, and analysis;
    Polymerase chain reaction

II. Organismal Biology - 33-34%

  • 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.

A. Animal Structure, Function, and Organization - 9-10%

  1. Exchange with environment
    Nutrient, salt, and water exchange
    Gas exchange; Energy

  2. Internal transport and exchange
    Circulatory, gastrovascular, and digestive systems

  3. Support and movement
    Support systems (external, internal, and hydrostatic)
    Movement systems (flagellar, ciliary, and muscular)

  4. Integration and control mechanisms
    Nervous and endocrine systems

  5. Behavior (communication, orientation, learning, and instinct)

  6. Metabolic rates (temperature, body size, and activity)

B. Animal Reproduction and Development - 5-6%

Reproductive structures

  1. Meiosis, gametogenesis, and fertilization

  2. Early development (e.g., polarity, cleavage, and gastrulation)

  3. Developmental processes (e.g., induction, determination, differentiation, morphogenesis, and metamorphosis)

  4. External control mechanisms (e.g., photoperiod)

C. Plant Structure, Function, and Organization, with Emphasis on Flowering Plants - 6-7%

Tissues, tissue systems, and organs

  1. Water transport, including absorption and transpiration

  2. Phloem transport and storage

  3. Mineral nutrition

  4. Plant energetics (e.g., respiration and photosynthesis)

D. Plant Reproduction, Growth, and Development, with Emphasis on Flowering Plants - 4-5%

Reproductive structures

  1. Meiosis and sporogenesis

  2. Gametogenesis and fertilization

  3. Embryogeny and seed development

  4. Meristems, growth, morphogenesis, and differentiation

  5. Control mechanisms (e.g., hormones, photoperiod, and tropisms)

E. Diversity of Life - 6-7%

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)

  • 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

III. Ecology and Evolution - 33-34%

  • 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.

A. Ecology - 16-17%

  • 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

B. Evolution - 16-17%

  • 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

GRE Subject Test: Chemistry