Texas STAAR Biology EOC — Practice, Retake Plan, and How to Pass

The Texas STAAR Biology End-of-Course (EOC) exam is one of the five state-mandated EOCs required for high-school graduation in Texas. This guide walks through what the test actually covers, how Texas reports performance levels, what counts as a passing score, the retake windows, the Individual Graduation Committee (IGC) backup path, and how to practice efficiently — in plain language, with no panic.

This is an independent guide. We are not affiliated with the Texas Education Agency (TEA), Cambium Assessment (the STAAR delivery vendor), or any Texas school district. Anything specific about score scales, schedules, or graduation requirements should be confirmed with your school counselor or the official TEA STAAR resources before you act on it.

Why STAAR Biology matters

Under Texas Education Code, a student earning the standard high-school diploma must take five STAAR EOCs: Algebra 1, English I, English II, Biology, and U.S. History. Biology is typically taken in 9th or 10th grade in most Texas high schools, depending on the district’s science sequence. A student must reach “Approaches Grade Level” on the Biology EOC to earn graduation credit toward the standard diploma — or pursue the Individual Graduation Committee (IGC) route if they don’t pass.

Biology is the only science EOC that’s a graduation requirement (Chemistry and Physics STAAR exams were discontinued years ago). That makes the Biology EOC the single science test that determines graduation eligibility for hundreds of thousands of Texas students each year.

Since the STAAR redesign in 2022-23, the exam is fully online, delivered through Cambium Assessment, and includes a mix of question types: multiple-choice, multi-select, equation/short-response, drag-and-drop, table completion, and a small number of short constructed-response items. The total test window is 4 hours. Expect roughly 50-54 scored items plus a small number of unscored field-test items. Confirm current details on the official TEA STAAR resources before the test date.

What does “passing” actually look like?

Texas reports STAAR Biology results in four performance levels, just like every other STAAR EOC:

• Did Not Meet Grade Level — below graduation standard.
• Approaches Grade Level — the minimum standard for graduation credit.
• Meets Grade Level — on-track performance.
• Masters Grade Level — advanced performance.

For graduation, “Approaches Grade Level” is the cutoff that matters. A student scoring at or above the Approaches scale score earns graduation credit on Biology. The exact scale-score threshold is set by the State Board of Education and posted on TEA’s assessment site — confirm the current number before testing.

One important point that confuses families: the classroom Biology grade and the Biology EOC are tracked separately. A student can pass Biology in class with a regular grade but still score below Approaches on the EOC. Both matter for graduation in different ways.

The retake schedule

Texas administers the STAAR Biology EOC in the same three windows as the other EOCs:

• December retake — typically early December. For students who didn’t pass earlier.
• Spring administration — typically late April through May. The main testing window for first-time takers.
• Summer retake — typically late June through July. The last window before the next school year.

Exact dates vary slightly each year and by district. Check with your school counselor or your district’s assessment calendar (Dallas ISD, Houston ISD, Austin ISD, NEISD, Plano ISD, and other large districts publish theirs on their websites).

What’s actually on the STAAR Biology EOC?

The STAAR Biology EOC is aligned to the Texas Essential Knowledge and Skills (TEKS) for Biology (TEC §112.34). TEA organizes the assessed standards into five Reporting Categories:

• Cell Structure and Function — cell types (prokaryotic vs eukaryotic), organelles, cell membranes and transport (diffusion, osmosis, active transport), photosynthesis and cellular respiration, the cell cycle, mitosis, and meiosis.
• Mechanisms of Genetics — DNA structure and replication, RNA and protein synthesis (transcription/translation), Mendelian genetics (Punnett squares, dominant/recessive, sex-linked), non-Mendelian patterns (codominance, incomplete dominance), and biotechnology (genetic engineering, PCR, GMOs).
• Biological Evolution and Classification — Darwin’s theory and natural selection, evidence for evolution (fossils, comparative anatomy, molecular biology), speciation, taxonomy and the binomial naming system, phylogenetic trees and cladograms, the six-kingdom classification system.
• Biological Processes and Systems — homeostasis, human body systems and their interactions (circulatory, respiratory, digestive, nervous, endocrine, immune, muscular, skeletal), plant systems (transport, photosynthesis-respiration interactions, reproduction, growth responses), and viral structure and replication.
• Interdependence within Environmental Systems — ecosystems and biomes, energy flow (producers, consumers, decomposers, food webs, energy pyramids), biogeochemical cycles (carbon, nitrogen, water), symbiotic relationships, population dynamics, ecological succession, and human impact on the environment.

Format-wise, expect multiple-choice (4-option), multi-select (pick more than one correct answer), drag-and-drop, table-completion items, items where the student selects from a drop-down list within a passage, and a small number of short constructed-response items.

Most items are auto-scored. There is no partial credit on auto-scored items, so a careful read of the question is just as important as knowing the biology.

The four most common Biology EOC failure patterns — and how to fix each

1. The student memorized vocab but can’t apply it. Biology is full of terms (mitochondria, ribosome, codominance, allele). Many students learn the definitions for class quizzes but can’t recognize the concept when it appears in an applied question on the EOC (“In the diagram below, which structure is responsible for ATP production?”). The fix: practice with applied EOC-style items, not flashcard definitions.

2. Diagrams and graphs are weak. The STAAR Biology EOC is heavy on diagrams — cell cross-sections, Punnett squares, phylogenetic trees, food webs, body system diagrams. Students who studied from text-heavy notes underperform on diagram-interpretation items. The fix: drill specifically with visual practice items, especially genetics (Punnett squares with two traits, sex-linked crosses) and cell biology (organelle identification).

3. Genetics calculations break down. Two-trait dihybrid crosses, blood-type Punnett squares (codominance), and sex-linked traits trip up a large minority of students. Spend extra time on Reporting Category 2 if any genetics practice items are missed.

4. Reading-heavy passages eat time. Biology EOC items often include a paragraph of context before the actual question. Students who read every word run out of time. The fix: practice reading the question first, then scanning the passage for only the relevant information.

How our Biology practice fits a STAAR Biology EOC plan

Texas CBE™ is a Texas-focused practice platform. Our Biology question bank is built around the Texas Essential Knowledge and Skills (TEKS) for Biology — the same TEKS standards that the STAAR Biology EOC tests. Cell structure, genetics, evolution, body systems, ecosystems — the same five Reporting Categories, tested with the same kinds of applied items.

The practical truth: STAAR Biology and Texas CBE Biology cover the same TEKS standards. Strong performance on our Biology practice bank transfers directly to the STAAR Biology EOC. Our items cover all five Reporting Categories with extra coverage on the high-leverage areas (genetics calculations, cell biology diagrams, ecology food-web items).

What we do not claim: we are not aligned to specific STAAR item specifications, and we are not the official TEA STAAR practice. The official TEA STAAR Biology sample items and online practice test should be part of every prep plan — they are free and show the exact item formats and the Cambium online platform. Use ours for volume, fluency, and topic coverage; use TEA’s for format and platform familiarity.

Want to see where your child actually stands? Try our Biology free sample — no signup, no payment. The sample covers cell structure, genetics, evolution, body systems, and ecology. If they score 85%+ on the sample cold (no review), they’re likely in Approaches range for the STAAR Biology EOC. If they score below 60%, the gap is bigger than “a little more practice” will close — useful information for planning. Related subjects: Algebra 1, U.S. History, Geometry, Algebra 2, Chemistry.

The Individual Graduation Committee (IGC) backup route

Under Texas Education Code §28.0258, a student who fails no more than two STAAR EOCs may be eligible for a graduation determination by an Individual Graduation Committee (IGC). The IGC is a school-level committee — principal, teacher of the failed subject, department head, counselor, and the student’s parent — that reviews the student’s overall academic record, completed coursework, attendance, and other evidence of mastery. The committee can determine that the student is qualified to graduate even without the EOC pass, provided the student meets the additional requirements the IGC sets (often a project, additional coursework, or a portfolio).

For Biology specifically, the IGC may require additional lab evidence, a research paper, or a science project. Different districts and campuses run IGCs differently — ask the school counselor early what their campus typically asks for.

An IGC is a real, statutory path — not a workaround. It exists in Texas Education Code specifically for this situation. But IGC eligibility caps out at two EOC failures; three or more typically removes eligibility.

A realistic 4-week practice plan

If the next test window is 4-6 weeks away, this is a defensible plan:

• Week 1 — diagnostic. Take TEA’s official sample items and a full mixed-topic practice set from any TEKS-aligned source. Identify the 2-3 weakest Reporting Categories. Don’t try to “cover everything.” Cover the weak spots.
• Week 2 — target the weaknesses. 30-45 minutes a day on the weak topics. For most students this is some combination of genetics calculations, cell organelles, and ecology cycles.
• Week 3 — mixed practice under time. Switch to mixed-topic, timed problem sets. The point now is execution and pacing, not learning new material. Track where questions take too long.
• Week 4 — full practice tests + rest. One or two full-length 4-hour practice sessions. Light review the last 2 days. The night before the test: sleep, not study.

What if the student has already retaken once and is still below Approaches?

Two parallel actions are usually right:

1. Continue working the EOC retake plan above — another attempt is not penalized, retakes are free, and the highest score counts.
2. Talk to the counselor about IGC eligibility. The IGC and the EOC retake are not mutually exclusive paths.

For Spanish-speaking families

STAAR Biology EOC items are presented in English. Practice in English — with vocabulary support where needed — is the realistic path. Our content is available in multiple languages for context, but the actual problem-solving practice should be in English.

How parents help without making it worse

Biology is a memorization-and-application subject. The fastest way for a parent to backfire is to drill flashcards at the dinner table. What works better: give the student a quiet 45-minute block, an aligned practice set, and step back. Then review the missed items together — not as a teacher, but as someone curious about which step broke. The student often diagnoses their own pattern within a week.

Sources and where to verify

• Texas Education Agency — STAAR Biology EOC assessed curriculum, blueprint, and Reporting Category breakdowns.
• Texas Education Code §28.0258 — Individual Graduation Committee eligibility and process.
• Texas Administrative Code, Chapter 101 — STAAR EOC administration and graduation requirements.
• TEA STAAR Online Practice Test and released items for Biology.
• Cambium Assessment — STAAR delivery platform documentation.

Always confirm current scores, dates, and rules with your school counselor before acting on them. This guide reflects publicly available information at the time of writing.

Looking for the bigger picture of all five STAAR EOCs? See our Complete 5 EOC Guide for Texas Families — covers Algebra 1, English I, English II, Biology, and U.S. History, plus the IGC backup path.

This is an independent guide. Texas CBE™ is not affiliated with the Texas Education Agency (TEA), Cambium Assessment, UT High School (UTHS), The University of Texas at Austin, the State Board of Education, Dallas ISD, Houston ISD, Austin ISD, NEISD, Plano ISD, or any other Texas school district. All trademarks belong to their respective owners.