SBI3U practice exam: Grade 11 Biology questions and exam rules

Each daily paper has 8 original questions worth 25 to 35 marks. The Grade 11 Biology (SBI3U) paper covers classification and diversity, cell division, gas exchange and transport in animals and plants; its biomolecules, enzymes and protein synthesis questions belong to SBI4U. The Grade 12 Biology paper has the inheritance and evolution questions that fit SBI3U's genetics and evolution strands.

How the SBI3U exam counts in 2026-27

In Grade 11 science in Ontario, your final mark is now 65% classroom work, a 25% written exam, and 10% attendance and participation, with the exam written in your board's exam period. The prerequisite for SBI3U is Grade 10 academic science. These figures come from the Ministry of Education's September 2026 update to Growing Success.

What's on the SBI3U exam: the strands

• Diversity of living things: classification and the main groups of organisms.
• Evolution: natural selection, evidence for evolution and speciation.
• Genetic processes: meiosis and patterns of inheritance.
• Animals: structure and function: the digestive, respiratory and circulatory systems.
• Plants: anatomy, growth and function.
• Scientific investigation skills and career exploration run through every unit.

SBI3U practice exam questions with answers

We wrote these for this page, one from each main strand.

1. Diversity. What is binomial nomenclature, and how should Ursus americanus (the black bear) be written? Answer: every species gets a two-part Latin name: the genus, then the species. The genus has a capital letter, the species name is lower case, and both are italicized (or underlined when handwritten), so Ursus americanus.

2. Evolution. A river splits a population of squirrels into two groups that can no longer meet. Explain how two species could form. Answer: with no interbreeding, the groups' gene pools change separately through mutation, natural selection in their different environments, and genetic drift. Over many generations they become so different that they couldn't produce fertile offspring even if they met again. This is allopatric speciation. Watch selection at work in the Natural Selection simulator.

3. Genetic processes. Two pea plants are both RrYy (round, yellow seeds dominant). What fraction of offspring will have wrinkled, green seeds (rryy)? Answer: each gene behaves independently: ¼ chance of rr and ¼ chance of yy, so ¼ × ¼ = 1/16. The full dihybrid ratio is 9 : 3 : 3 : 1. The Genetics Cross Calculator draws the full Punnett square.

4. Animal systems. A resting heart beats 70 times a minute with a stroke volume of 75 mL. What is the cardiac output? Answer: cardiac output = heart rate × stroke volume = 70 × 75 = 5,250 mL/min, or 5.25 L/min. Try a cardiac output question from our Human Physiology course, then press Mark.

5. Plants. Compare what xylem and phloem carry. Answer: xylem carries water and dissolved minerals up from the roots, pulled mainly by transpiration from the leaves. Phloem carries sugars made in photosynthesis from the leaves to where they are used or stored, in either direction.

Use the daily papers as practice exams

1. Use the SBI3U paper most days, and the SBI4U paper when you revise genetics and evolution.
2. Work to the suggested time, 35 to 45 minutes.
3. Skip questions on biomolecules, enzymes and protein synthesis: they belong to SBI4U.
4. Mark each paper and note which strand each lost mark belongs to.

Common SBI3U mistakes

• Capitalizing the species name in binomial nomenclature.
• Saying organisms evolve because they need to: selection acts on variation that already exists.
• Adding probabilities for independent genes instead of multiplying.
• Mixing up xylem and phloem.
• Confusing mitosis and meiosis in genetics questions.

Read next

Canada · Grade 11SPH3U Practice Exam: Grade 11 Physics Questions, AnswersAn SPH3U practice exam: free Grade 11 Physics questions on kinematics, forces, energy, sound and circuits, with answers, plus how the 2026-27 exam counts.