PRAXISCode: 5236Biology🔬 NGSS Aligned40%+ SEP Questions
Praxis® Biology: Content Knowledge (5236)
Practice Test & Study Guide
Comprehensive preparation for prospective biology teachers — covering all 5 official content categories and the Science and Engineering Practices (SEPs) that appear in more than 40% of exam questions.
150
Questions
2.5 hrs
Time limit
~150
Passing score*
5
Content categories
$130
Exam fee
4.9 · 12,400
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More than 40% of questions integrate Science and Engineering Practices (SEPs). The Praxis Biology exam goes beyond content recall — it tests how well you apply biological knowledge using the 8 SEPs from the NGSS Framework (asking questions, analyzing data, constructing explanations, etc.). Additionally, approximately 25% of questions apply content to teaching scenarios, asking how a biology teacher would use this knowledge in instruction, curriculum, or student assessment.
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Source: All exam details are drawn from the official ETS Praxis Biology (5236) Study Companion. The exam aligns to NSTA Preparation Standards and the NGSS Framework. Passing scores vary by state — always confirm at ets.org/praxis/states.
Free Praxis Biology: Content Knowledge (5236) Sample Quiz
1 / 2Which adaptation allows desert mammals such as the kangaroo rat to survive without drinking liquid water?
Praxis Biology: Content Knowledge (5236) — Test at a Glance
Key facts directly from the official ETS test specifications.
TEST NAME
Biology: CK
Praxis Subject Assessment
TEST CODE
5236
Computer-delivered
TOTAL QUESTIONS
150
All selected-response
TIME LIMIT
2.5 hrs
150 minutes
SEP QUESTIONS
>40%
NGSS-integrated
REGISTRATION FEE
$130
Paid to ETS at registration
TYPICAL PASSING SCORE
~150
Scaled; varies by state
SCORE REPORTING
~5 wks
After test date
About the Praxis Biology: Content Knowledge (5236) Exam
What you need to know before you register.
The Praxis Biology: Content Knowledge (5236) is designed to measure the knowledge and competencies important for safe and effective beginning practice as a teacher of biology. Test takers have typically completed a bachelor's degree program with appropriate coursework in biology and education.
The assessment was developed through work with practicing biology teachers, teacher educators, and higher education biology specialists. Content and practices measured reflect the Disciplinary Core Ideas (DCIs) and Science and Engineering Practices (SEPs) established by the National Research Council in the Framework for K-12 Science Education and included in the Next Generation Science Standards (NGSS). The exam also aligns to the National Science Teaching Association (NSTA) Preparation Standards for biology.
A distinctive feature of this exam is that more than 40% of questions integrate one or more Science and Engineering Practices (SEPs) — meaning they don't just test whether you know biology content but whether you can reason like a scientist. Additionally, approximately 25% of questions apply content to teaching scenarios, asking how a teacher would use biological knowledge in instruction, curriculum design, or student assessment.
The 150 questions measure concepts, terms, phenomena, methods, applications, data analysis, and problem solving in biology. Questions span all five content categories and draw on knowledge ranging from molecular biology and genetics through ecology and environmental science. The exam may contain some questions that will not count toward your score.
Official Exam Blueprint: 5 Content Categories
The official ETS blueprint defines 5 content categories. Genetics and Evolution is the largest at 26% — and remember that 40%+ of all questions across every category also integrate SEPs.
Category I
Nature and Impact of Science and Engineering
Nature of scientific knowledge; experimental design and data analysis; laboratory procedures and safety; engineering design; science, technology, society, and the environment; applications in public health, medicine, and agriculture including biotechnology and epidemiology.
13%
19 questions
Category II
Cell Biology: Cell Structure and Function
Basic biochemistry and metabolism; macromolecules (nucleic acids, proteins, lipids, carbohydrates); enzyme structure and kinetics; major biochemical pathways (photosynthesis, cellular respiration, fermentation); cell structure and organelles; membrane transport; cell signaling; eukaryotic cell division and the cell cycle.
22%
33 questions
Category III
Genetics and Evolution
Nucleic acid and chromosome structure; central dogma; DNA replication, transcription, translation; gene regulation; mutations; Mendelian and non-Mendelian genetics; genetic variation; mechanisms of evolution (natural selection, Hardy-Weinberg, genetic drift); evidence for evolution; speciation; origin of life; species extinction.
26%
39 questions
Category IV
Diversity of Life and Organismal Biology
Biological classification; taxonomic hierarchy; viruses, eubacteria, archaea, protists, fungi, plants, and animals; cell differentiation and stem cells; animal biology including human organ systems and homeostasis; reproduction and development; animal behavior; plant biology including structure, transport, reproduction, and hormones.
20%
30 questions
Category V
Ecology: Organisms and Environments
Biosphere organization; species relationships (symbiosis, predation, competition); population growth (exponential, logistic); human impacts on ecosystems; ecological succession; biomes and energy flow; trophic levels and food webs; biogeochemical cycles (water, carbon, nitrogen, phosphorus).
19%
29 questions
Science and Engineering Practices (SEPs) — 40%+ of All Questions
SEPs are not a separate test section — they are integrated throughout all 5 content categories. Questions that incorporate SEPs ask you to do something with biological knowledge, not just recall it. Understanding all 8 practices before test day is essential.
Asking Questions
Ask questions arising from observations, models, or unexpected results; frame hypotheses; identify what can be investigated with available resources.
Developing and Using Models
Evaluate, revise, and apply models to explain natural phenomena; distinguish between a model and the phenomenon it represents.
Planning and Carrying Out Investigations
Design experiments; identify variables and controls; plan data collection; evaluate investigation methods for accuracy and precision.
Analyzing and Interpreting Data
Process and organize quantitative and qualitative data; identify patterns; draw valid conclusions; perform error analysis.
Using Mathematics and Computational Thinking
Apply mathematical representations; use scientific notation, dimensional analysis, and significant figures; interpret quantitative relationships.
Constructing Explanations
Apply scientific theories to explain phenomena; revise explanations based on evidence; distinguish between explanations and descriptions.
Engaging in Argument from Evidence
Evaluate competing explanations using evidence; critique arguments; identify strengths and weaknesses of scientific claims.
Obtaining, Evaluating, and Communicating Information
Read and evaluate scientific texts and data; compare sources for accuracy; communicate results in multiple formats.
Key Topics by Content Category
Focus your study on these specific competencies — drawn directly from the official ETS content specifications.
I
Nature and Impact of Science and Engineering
~19 questions · 13%
Nature of scientific knowledge: how understanding develops; distinguishing laws, theories, and hypotheses; role of models
Scientific skills: observing, categorizing, comparing, generalizing, inferring, and concluding; interdisciplinary nature of science
Experimental design: hypothesis development, identifying variables (independent, dependent, controlled), planning data collection
Data analysis: processing quantitative and qualitative data; scientific notation; significant figures; dimensional analysis; unit conversion
Error analysis: identifying sources and effects of error; extrapolating and drawing valid conclusions from data
Laboratory procedures: preparation of materials; safe use, storage, and disposal of chemicals and biological materials; safety and emergency procedures
Engineering design: defining problems (criteria and constraints); designing and evaluating solutions; optimizing through systematic modification
Science-technology-society: interdependence of science, engineering, and technology; how engineering advances drive scientific discoveries
Environmental impacts: air/water pollution, greenhouse gases, global climate change, deforestation, habitat fragmentation, invasive species, ocean acidification
Conservation: species protection, habitat preservation, reforestation, captive breeding programs, remediation strategies
Public health applications: epidemiology, disease transmission, vaccines, HIV/AIDS, pandemics; biotechnology (GMOs, genetic engineering)
Ethical issues: use of stem cells, cloning, genetic information, toxic chemicals in research; ethical use of technology and organisms
II
Cell Biology: Cell Structure and Function
~33 questions · 22%
Chemical structures: atomic and molecular structures; chemical bonding; organic vs. inorganic molecules; properties of water
Macromolecules: nucleic acids, proteins, lipids, and carbohydrates — structure and function; structural vs. functional differences (e.g., starch vs. cellulose)
Enzyme structure and function: active site and substrate binding; energy profile; effects of temperature, pH, concentration, and inhibitors on reaction kinetics
Enzyme regulation: cooperative binding, feedback inhibition; allosteric regulation
Biochemical pathways: cellular locations; ATP structure; photosynthesis (photosystems I and II, electron transport chain, Calvin-Benson cycle)
Cellular respiration: glycolysis, citric acid (Krebs) cycle, oxidative phosphorylation; aerobic vs. anaerobic; fermentation; chemosynthesis
Cell theory and characteristics of life: obtaining energy, homeostasis, growth, reproduction; prokaryotic vs. eukaryotic; plant vs. animal cells
Cell organelles: membrane-bound organelles, ribosomes, cytoskeleton, extracellular matrix; organelle abundance based on cell function
Membrane structure and transport: phospholipid bilayer; active and passive transport; osmosis and water potential; facilitated diffusion
Cell communication: cell surface proteins; signal molecules; signal transduction pathways; exocytosis and endocytosis
Feedback mechanisms: negative and positive feedback; homeostatic regulation
Cell cycle and division: cell cycle stages and checkpoints; mitosis stages and results; cytokinesis (animal vs. plant); cancer and unregulated cell proliferation
III
Genetics and Evolution
~39 questions · 26%
Nucleic acid structure: sugar-phosphate backbone; complementary base pairing; DNA vs. RNA; chromosome structure (nucleosomes, telomeres)
Central dogma: DNA replication; transcription; pre-mRNA processing; translation (roles of mRNA, tRNA, rRNA, ribosomes); genetic code chart
Gene regulation: promoters, enhancers, transcription factors; posttranslational regulation; differential gene expression in eukaryotes vs. prokaryotes
Mutations: causes; types (substitution, deletion, insertion, inversion, translocation); disorders from point mutations and frameshift mutations; somatic vs. germline mutations
Laboratory techniques: microscopy types; gel electrophoresis; spectrophotometry; PCR; genome sequencing; gene therapy; transgenic organisms; chromosome analysis
Mendelian genetics: dominant and recessive alleles; law of segregation; law of independent assortment; monohybrid and dihybrid crosses; pedigree analysis
Non-Mendelian inheritance: gene linkage; sex-linked inheritance; multiple alleles; codominance; incomplete dominance; polygenic inheritance; epistasis; epigenetics
Sources of genetic variation: mutation; crossing-over; random fertilization; horizontal genetic exchange (conjugation, transformation, transduction)
Mechanisms of evolution: natural selection; Hardy-Weinberg equilibrium (calculations and assumptions); gene flow; genetic drift (bottleneck and founder effects)
Patterns of evolution: convergent, divergent, coevolution, parallel, adaptive radiation; gradualism vs. punctuated equilibrium; macroevolution vs. microevolution
Speciation: reproductive isolation mechanisms; allopatric and sympatric speciation; phylogenetic trees and cladograms; molecular clock (mitochondrial DNA)
Evidence for evolution: fossil record; biogeographical similarities; endosymbiosis; homologous structures; embryology; vestigial structures; molecular evidence
IV
Diversity of Life and Organismal Biology
~30 questions · 20%
Biological classification: taxonomic hierarchy (domains and kingdoms); binomial nomenclature; phylogenetic classification based on rRNA
Defining characteristics of viruses, eubacteria, archaea, protists, fungi, plants, and animals — structural, nutritional, and reproductive modes
Cell differentiation: differential gene expression; stem cells (characteristics and sources); organizational hierarchy (cells → tissues → organs → organ systems)
Animal biology: major evolutionary trends (body plans, body cavities, cephalization, bilateral vs. radial symmetry); endotherm vs. ectotherm; coelomates vs. pseudocoelomates
Human organ systems: cardiovascular and respiratory; digestive and excretory; immune; musculoskeletal; nervous and endocrine; reproductive — structure and function
Homeostasis in animals: role of kidney, adrenals, hypothalamus, pituitary; insulin, ADH, sex hormones; negative and positive feedback; behavioral homeostasis
Reproduction and development: meiosis stages and chromosome changes; fertilization; embryonic development; metamorphosis; growth patterns
Animal behavior: innate vs. learned; territoriality; social behavior (hunting, flocking, migration, altruism); group vs. individual selection
Plant characteristics: vascular vs. nonvascular; angiosperms vs. gymnosperms; monocots vs. eudicots; plant tissues (dermal, ground, vascular — xylem and phloem)
Plant transport: water and nutrient transport through xylem; transpiration through stomata; guard cell mechanism; phloem transport; photosynthesis products
Plant reproduction: gametogenesis; alternation of generations (gametophyte and sporophyte); pollination strategies; seed and spore propagation; germination
Plant hormones and responses: auxin, gibberellins, ethylene, cytokinins; plant tropisms; physical and chemical defenses
V
Ecology: Organisms and Environments
~29 questions · 19%
Hierarchical structure: biosphere → biomes → ecosystems → communities → populations → organisms; characteristics of aquatic and terrestrial biomes
Species relationships: mutualism, parasitism, commensalism; predator-prey relationships and evolutionary adaptations; competition; keystone species
Population growth: r-strategists vs. K-strategists; exponential growth; logistic growth and carrying capacity; population demographics
Community structure: limiting factors; habitat and niche; density-dependent vs. density-independent factors; biotic and abiotic components
Human impacts: habitat destruction (deforestation, fragmentation, urbanization); pollution (plastics, acid precipitation, CFCs); climate change; invasive species
Remediation: reforestation, movement corridors, captive breeding, biotechnology applications; conservation strategies
Ecological succession: primary vs. secondary succession; biomass, diversity, productivity, and habitat changes during succession
Energy flow: trophic levels; pyramids of numbers, biomass, and energy; food chains, food webs, and trophic cascades; biomagnification
Biogeochemical cycles: water cycle; carbon cycle; nitrogen cycle (nitrogen fixation, nitrification, denitrification); phosphorus cycle — biotic and abiotic components
Ocean and freshwater ecology: density of water; coastal vs. inland temperatures; limiting factors for primary production in aquatic systems
Climate and biome interactions: greenhouse gases; ocean acidification; deforestation effects on carbon cycle; effects of fire, climate, and disease as disturbances
Applied ecology: eutrophication from agricultural runoff; acid precipitation; habitat fragmentation effects on genetic diversity; population viability analysis
Registration, Test Day & Scoring
Everything you need to know before and on exam day.
Registration
Where to registerpraxis.ets.org
Exam fee$130
Testing formatsIn-person or remote
ID required2 forms of valid ID
Arrive (in-person)15–30 min early
Scoring
Score typeScaled score
Raw score basisCorrect answers only
Typical passing score~150 (varies by state)
Results available~5 weeks post-test
State requirementsets.org/praxis/states
In-Person Testing
Test centersPrometric locations
Personal itemsStored in locker
Scratch paperProvided at station
Admission ticketPrint from ETS account
Remote Testing
DeviceLaptop/desktop only
No touchscreensTablets not allowed
Browser requiredETS Secure Test Browser
Equipment neededWebcam, mic, speakers
Passing Score Requirements by State
The Praxis Biology (5236) is used by many states for secondary biology teacher certification, but passing scores are not uniform.
Important: The passing score is generally around 150, though the exact requirement varies by state or licensing agency. A score that meets requirements in one state may not meet requirements in another. Always verify the exact passing score for your state at ets.org/praxis/states before registering.
Your raw score (number of correct answers) is converted to a scaled score that accounts for minor difficulty differences between test editions. There is no penalty for wrong answers, so always answer every question — never leave one blank. Some questions on the exam are unscored pretest items — you won't know which ones — so treat every question equally.
How to Prepare for the Praxis Biology Exam
Strategies aligned to the exam's NGSS-based design, SEP integration, and teaching scenario questions.
Genetics and Evolution is 26% of the exam — the largest single category. With ~39 questions, Category III covers molecular genetics (central dogma, gene regulation, mutations), Mendelian and non-Mendelian genetics, all mechanisms of evolution, Hardy-Weinberg calculations, speciation, and evidence for evolution. Master this category first and return to it most often during your study plan.
Prepare for SEP-integrated questions, not just content recall. More than 40% of questions integrate Science and Engineering Practices — meaning you'll need to analyze data, evaluate experimental designs, interpret graphs, and construct explanations using biological content. Practice using biology content in data analysis and experimental reasoning contexts, not just memorizing facts.
Study the 8 SEPs as a framework, not as trivia. The SEPs — asking questions, developing models, planning investigations, analyzing data, using mathematics, constructing explanations, arguing from evidence, and communicating information — appear across all 5 content categories. Understanding what each practice means in a biology context will help you recognize and answer SEP-integrated questions even when the biology content is familiar.
Practice teaching scenario questions (~25% of the exam). These questions place biological content in an instructional context: how would you explain this concept to students, evaluate student work, choose instructional materials, or design an assessment? These require both deep content knowledge and pedagogical thinking. Review the "Tasks of Teaching Science" section in the official ETS Study Companion for examples.
Hardy-Weinberg calculations are frequently tested — know them cold. The Hardy-Weinberg equilibrium (p² + 2pq + q² = 1; p + q = 1) and the 5 conditions required for it appear regularly, often integrated with data interpretation. Practice calculating allele and genotype frequencies from population data and predicting the effect of violating each Hardy-Weinberg assumption.
Know all 5 biogeochemical cycles in detail. The water, carbon, nitrogen, phosphorus cycles — including specific organisms involved (nitrogen-fixing bacteria, nitrifying bacteria), reservoirs, and human impacts on each cycle — are consistently tested in the Ecology category. Eutrophication from nitrogen and phosphorus runoff is a specific, frequently tested application.
Download the official ETS Study Companion and work through all discussion questions. The free PDF contains content topics for all 5 categories plus open-ended discussion questions that directly model the kind of integrated, applied reasoning the exam requires. The Science and Engineering Practices and Tasks of Teaching Science sections are especially valuable — many candidates skip these and lose a significant portion of their potential score.
Frequently Asked Questions
Answers sourced from the official ETS Praxis Biology (5236) Study Companion and Mometrix test preparation resources.
How many questions are on the Praxis Biology: Content Knowledge (5236)?+
The exam contains 150 selected-response questions with a 2.5-hour (150-minute) time limit. Questions span 5 content categories: Nature and Impact of Science and Engineering (19 questions, 13%), Cell Biology (33 questions, 22%), Genetics and Evolution (39 questions, 26%), Diversity of Life and Organismal Biology (30 questions, 20%), and Ecology (29 questions, 19%). More than 40% of questions integrate Science and Engineering Practices (SEPs).
What is the passing score for the Praxis Biology (5236)?+
The passing score is generally around 150, though the exact requirement varies by state or licensing agency. Always verify the specific requirement for your state at ets.org/praxis/states before registering.
What are Science and Engineering Practices (SEPs)?+
SEPs are 8 practices from the NGSS Framework that scientists and engineers use to investigate and explain the world. More than 40% of Praxis Biology questions integrate one or more SEPs — including asking questions, developing models, planning investigations, analyzing data, using mathematics, constructing explanations, arguing from evidence, and communicating information. SEPs are woven throughout all 5 content categories, not tested in a separate section.
What content categories are on the Praxis Biology (5236)?+
The exam covers 5 official content categories: (I) Nature and Impact of Science and Engineering — 13%, 19 questions; (II) Cell Biology: Cell Structure and Function — 22%, 33 questions; (III) Genetics and Evolution — 26%, 39 questions; (IV) Diversity of Life and Organismal Biology — 20%, 30 questions; and (V) Ecology: Organisms and Environments — 19%, 29 questions.
What standards is the Praxis Biology exam aligned to?+
The exam aligns to the National Science Teaching Association (NSTA) Preparation Standards for biology, the Disciplinary Core Ideas (DCIs) and Science and Engineering Practices (SEPs) from the National Research Council's Framework for K-12 Science Education, and the Next Generation Science Standards (NGSS). Content was developed with practicing biology teachers, teacher educators, and higher education biology specialists.
What question formats appear on the Praxis Biology exam?+
The exam uses multiple selected-response formats: single-selection multiple-choice, hot spot (click on a location in a graphic), drop-down menu selection, numeric entry, sentence selection, and drag-and-drop. Familiarity with non-standard formats like hot spot and drag-and-drop before test day is important since they appear alongside standard multiple choice questions.
How much does the Praxis Biology exam cost?+
The registration fee is $130, paid directly to ETS at praxis.ets.org.
When will I receive my Praxis Biology scores?+
Official score reports are typically available approximately five weeks after your test date. Scores are posted to your ETS account and sent to any institutions you designated at registration.
Ready to Start Practicing?
Adaptive questions aligned to all 5 official ETS content categories — including SEP-integrated and teaching scenario questions. Domain-level analytics so you know exactly where to focus.
Get Free Access — No Credit Card NeededSources: ETS Praxis Biology: Content Knowledge (5236) Study Companion (official PDF, ets.org); ETS Praxis Test Schedule 2025–26; National Research Council — A Framework for K-12 Science Education; NSTA Preparation Standards for Biology. Praxis® is a registered trademark of Educational Testing Service (ETS). This site is not affiliated with or endorsed by ETS. Passing score requirements vary by state — always verify at ets.org/praxis/states.
Last Updated: May 10, 2026