Louisiana high school biology questions built on a finding, a count or a model, each tied to its standard.
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Unofficial practice questions, not affiliated with the Louisiana Department of Education. Bank checked October 9, 2026.
The real test: LEAP Biology
What counts
5 item sets, 1 task set and 16 standalone items, worth 67 points. One more set and four standalone items are field-test questions that do not count.
Sessions
Three timed sessions of 75, 90 and 75 minutes: 4 hours in all. The task set, with its extended response, is in session 2.
Kinds of questions
Multiple choice with four options, multiple select, technology-enhanced and two-part items worth up to 2 points, constructed responses on a 2-point rubric and o
What is reported
Three categories: Investigate, Evaluate and Reason Scientifically. The extended response counts in the overall score only.
When it is given
In 2026-2027: November 30 to December 18, April 1 to May 12 and June 21 to June 25.
Scores
Five achievement levels: Unsatisfactory, Approaching Basic, Basic, Mastery and Advanced. The guide gives no percent to pass.
A cell reads messenger RNA three bases at a time. What does each three-base codon stand for?National Human Genome Research Institute (NIH), Talking Glossary: Codon
A fertilized egg divides again and again. Its cells become nerve, muscle and blood cells, yet all carry the same DNA. What explains the different cell types?Louisiana Student Standards for Science, performance expectation HS-LS1-4 and its core ideas, as printed in the department's Crosswalk for Biology
A gene in the nucleus is copied into messenger RNA. What happens to the messenger RNA next?National Human Genome Research Institute (NIH), Talking Glossary: Translation
A skin cell divides by mitosis. How do the two daughter cells compare with the parent cell?National Human Genome Research Institute (NIH), Talking Glossary: Mitosis
A student's heart rate is 70 beats per minute at rest, 132 just after a run and 72 five minutes later. What does the return toward 70 show?Louisiana Student Standards for Science, performance expectation HS-LS1-3 and its core ideas, as printed in the department's Crosswalk for Biology
Show all 54 questions (49 more)
Cells and body systems, continued
An artery wall has elastic tissue and smooth muscle that adjust how much blood passes through. What does this show about body systems?Louisiana Student Standards for Science, performance expectation HS-LS1-2 and its core ideas, as printed in the department's Crosswalk for Biology
During a sprint, a runner's muscles use oxygen faster, and both breathing rate and heart rate rise. Which model explains this?Louisiana Student Standards for Science, performance expectation HS-LS1-2 and its core ideas, as printed in the department's Crosswalk for Biology
In a model of the cell cycle, a checkpoint stops a damaged cell from dividing. What can result when mutations disable such controls?National Human Genome Research Institute (NIH), Talking Glossary: Cancer
One base in a plant's pigment gene is changed. The pigment protein now has one different amino acid, and the flowers are white instead of purple. Which explanation fits?National Human Genome Research Institute (NIH), Talking Glossary: Protein
Students want evidence that the body keeps heart rate in check after exercise. Which plan is best?Louisiana Student Standards for Science, performance expectation HS-LS1-3 and its core ideas, as printed in the department's Crosswalk for Biology
Which list runs from the smallest level of organization to the largest in a multicellular organism?Louisiana Student Standards for Science, performance expectation HS-LS1-2 and its core ideas, as printed in the department's Crosswalk for Biology
Which question could be answered by an investigation of homeostasis in plants?Louisiana Student Standards for Science, performance expectation HS-LS1-3 and its core ideas, as printed in the department's Crosswalk for Biology
Matter and energy 11
A DNA nucleotide has a sugar, a phosphate group and a nitrogen-containing base. Sugar supplies carbon, hydrogen and oxygen. Which elements must a cell get from other molecules to build nucleotides?National Human Genome Research Institute (NIH), Talking Glossary: Nucleotide
A grassland supports thousands of grasshoppers, hundreds of mice and only a few hawks. Which claim does this pattern support?Louisiana Student Standards for Science, performance expectation HS-LS2-4 and its core ideas, as printed in the department's Crosswalk for Biology
A model compares aerobic and anaerobic cellular respiration. What is the difference between them?Louisiana Student Standards for Science, performance expectation HS-LS1-7 and its core ideas, as printed in the department's Crosswalk for Biology
A model of photosynthesis shows matter going in and matter coming out. Which two substances go in?Louisiana Student Standards for Science, performance expectation HS-LS1-5 and its core ideas, as printed in the department's Crosswalk for Biology
A plant makes sugar in its leaves. Later, carbon atoms from that sugar turn up in the plant's proteins. Which explanation fits?Louisiana Student Standards for Science, performance expectation HS-LS1-6 and its core ideas, as printed in the department's Crosswalk for Biology
A water plant under a bright lamp gives off 40 gas bubbles a minute. Under a dim lamp it gives off 12. What is the gas, and what does the result show?Louisiana Student Standards for Science, performance expectation HS-LS1-5 and its core ideas, as printed in the department's Crosswalk for Biology
In a model of a pond, producers store 20,000 kilojoules of energy. The model passes 10 percent of the energy at each level to the next. How much reaches the secondary consumers?Louisiana Student Standards for Science, performance expectation HS-LS2-4 and its core ideas, as printed in the department's Crosswalk for Biology
In a model of photosynthesis, what happens to the light energy a leaf absorbs?Louisiana Student Standards for Science, performance expectation HS-LS1-5 and its core ideas, as printed in the department's Crosswalk for Biology
On a cold morning a runner loses heat to the air, yet body temperature stays near normal. Which process releases the energy that keeps the body warm?Louisiana Student Standards for Science, performance expectation HS-LS1-7 and its core ideas, as printed in the department's Crosswalk for Biology
Which process in the carbon cycle takes carbon dioxide out of the atmosphere?Louisiana Student Standards for Science, performance expectation HS-LS2-4 and its core ideas, as printed in the department's Crosswalk for Biology
Which statement about matter belongs in a correct model of cellular respiration?Louisiana Student Standards for Science, performance expectation HS-LS1-7 and its core ideas, as printed in the department's Crosswalk for Biology
Inheritance and variation 9
A brother and sister have the same two parents, yet they differ in many inherited traits. Which claim does the evidence support?National Human Genome Research Institute (NIH), Talking Glossary: Crossing Over
A cross of two Pp plants is expected to give purple and white flowers in a 3 to 1 ratio. Of 400 offspring, 290 are purple and 110 are white. Which conclusion is best?Louisiana Student Standards for Science, performance expectation HS-LS3-3 and its core ideas, as printed in the department's Crosswalk for Biology
A stretch of DNA contains no gene. When it is removed, a nearby gene makes far more protein than before. Which question follows from this?Louisiana Student Standards for Science, performance expectation HS-LS3-1 and its core ideas, as printed in the department's Crosswalk for Biology
Adult height in a population forms a smooth range of values with most people near the middle, not two separate groups. What best explains this distribution?National Human Genome Research Institute (NIH), Talking Glossary: Polygenic Trait
In one plant species, the allele for purple flowers (P) is dominant to the allele for white flowers (p). Two Pp plants are crossed. What is the probability that an offspring has white flowers?National Human Genome Research Institute (NIH), Talking Glossary: Recessive Traits and Alleles
Two tall pea plants are crossed, and some of the offspring are short. Which question would best clarify how the trait is passed on?Louisiana Student Standards for Science, performance expectation HS-LS3-1 and its core ideas, as printed in the department's Crosswalk for Biology
Ultraviolet light causes a mutation in one skin cell on a person's arm. Can this mutation be inherited by the person's children?National Human Genome Research Institute (NIH), Talking Glossary: Mutation (and Mutagen, for ultraviolet radiation)
Which list names three sources of inheritable genetic variation?Louisiana Student Standards for Science, performance expectation HS-LS3-2 and its core ideas, as printed in the department's Crosswalk for Biology
Which statement correctly relates DNA, genes and chromosomes?Louisiana Student Standards for Science, performance expectation HS-LS3-1 and its core ideas, as printed in the department's Crosswalk for Biology
Natural selection and evolution 13
A field is sprayed with the same insecticide every year. The share of insects that survive spraying rises from 2 percent to 40 percent in six years. Which explanation do the data support?Louisiana Student Standards for Science, performance expectation HS-LS4-3 and its core ideas, as printed in the department's Crosswalk for Biology
A fish lays thousands of eggs each year, yet the number of adults in its pond stays about the same. Which factor in natural selection does this show?Louisiana Student Standards for Science, performance expectation HS-LS4-2 and its core ideas, as printed in the department's Crosswalk for Biology
A river changes course and divides a population of ground squirrels. After thousands of generations in different conditions, the two groups can no longer breed with each other. Which claim does this support?Louisiana Student Standards for Science, performance expectation HS-LS4-5 and its core ideas, as printed in the department's Crosswalk for Biology
A storm kills most of the lizards on a small island at random. The few survivors happen to be mostly striped, and so are their descendants. Which mechanism changed the population?National Human Genome Research Institute (NIH), Talking Glossary: Genetic Drift
A wetland dries up within a few decades. A frog species that breeds only in standing water disappears from the region. Which claim does this support?Louisiana Student Standards for Science, performance expectation HS-LS4-5 and its core ideas, as printed in the department's Crosswalk for Biology
Crabs prey on snails. Of 200 thick-shelled snails, 150 survive a season. Of 200 thin-shelled snails, 60 survive. Shell thickness is heritable. What do the numbers predict?Louisiana Student Standards for Science, performance expectation HS-LS4-3 and its core ideas, as printed in the department's Crosswalk for Biology
DNA sequences, amino acid sequences, anatomy and embryos all give the same branching pattern for a group of species. Why does this matter?Louisiana Student Standards for Science, performance expectation HS-LS4-1 and its core ideas, as printed in the department's Crosswalk for Biology
During a drought only large, tough seeds remain. Birds with deeper beaks crack them, and other birds go hungry. Which factor in natural selection do the scarce seeds represent?Louisiana Student Standards for Science, performance expectation HS-LS4-2 and its core ideas, as printed in the department's Crosswalk for Biology
In a rabbit population, a mutation gives some rabbits thicker fur. What must be true for natural selection to act on fur thickness?Louisiana Student Standards for Science, performance expectation HS-LS4-2 and its core ideas, as printed in the department's Crosswalk for Biology
The same gene is 300 bases long in four species. Compared with species W, species X differs at 2 bases, species Y at 9 and species Z at 21. Which species is most closely related to W?Louisiana Student Standards for Science, performance expectation HS-LS4-1 and its core ideas, as printed in the department's Crosswalk for Biology
Three mammals use their forelimbs to fly, to swim and to grasp. The bones inside are arranged in the same pattern. What is this evidence of?Louisiana Student Standards for Science, performance expectation HS-LS4-1 and its core ideas, as printed in the department's Crosswalk for Biology
Which statement separates natural selection from genetic drift?Louisiana Student Standards for Science, performance expectation HS-LS4-4 and its core ideas, as printed in the department's Crosswalk for Biology
Wind carries pollen from a distant field into a population of wildflowers and brings in alleles the population lacked. What is this movement of alleles called?Louisiana Student Standards for Science, performance expectation HS-LS4-4 and its core ideas, as printed in the department's Crosswalk for Biology
Ecosystems 9
A highway divides a forest, and engineers propose a wildlife bridge over it. What should they weigh when they evaluate the design?Louisiana Student Standards for Science, performance expectation HS-LS2-7 and its core ideas, as printed in the department's Crosswalk for Biology
A plant from another continent spreads through a marsh and crowds out the native plants. What is the most likely effect on the marsh?NOAA National Ocean Service, What is an invasive species?
A small fire burns part of a forest. Within a few decades the same kinds of trees and animals are back. What does this show about the ecosystem?Louisiana Student Standards for Science, performance expectation HS-LS2-6 and its core ideas, as printed in the department's Crosswalk for Biology
A town restores a marsh to reduce the effects of nearby building. Which data would best show whether the solution is working?Louisiana Student Standards for Science, performance expectation HS-LS2-7 and its core ideas, as printed in the department's Crosswalk for Biology
Deer were counted on an island every five years: 50, 120, 260, 400, 410, 395, 405. What is the best estimate of the island's carrying capacity for deer?Louisiana Student Standards for Science, performance expectation HS-LS2-1 and its core ideas, as printed in the department's Crosswalk for Biology
For 30 years, counts of fish, insects and plants in a lake rise and fall a little but stay within a narrow range. What does this indicate?Louisiana Student Standards for Science, performance expectation HS-LS2-6 and its core ideas, as printed in the department's Crosswalk for Biology
Nutrients wash off farm fields into a bay. Algae bloom and die, bacteria that digest them use up the oxygen, and fish die. Which solution acts on the cause?NOAA National Ocean Service, What is eutrophication?
Which change would lower an island's carrying capacity for deer?Louisiana Student Standards for Science, performance expectation HS-LS2-1 and its core ideas, as printed in the department's Crosswalk for Biology
Which disturbance is most likely to leave a very different ecosystem in place of the old one?Louisiana Student Standards for Science, performance expectation HS-LS2-6 and its core ideas, as printed in the department's Crosswalk for Biology
Unofficial practice for the LEAP 2025 Biology test of Louisiana high schools. Every question is this site's own, written from the state's assessment guide and life science standards. Not affiliated with the Louisiana Department of Education.
Read the full guide
Questions start from an event
The real test anchors each set and each standalone item to a phenomenon, something observed. So most questions here give a short finding first (a count, a cross, a change in a population), and the answer has to explain it.
Three categories, nineteen expectations
The guide sorts 19 performance expectations into Investigate (2), Evaluate (8) and Reason Scientifically (9), and this bank follows that spread. Each explanation ends with its expectation and category.
When a question gives numbers, work out the rate or the ratio before you read the choices.
Questions and answers
How many questions are on the LEAP 2025 Biology test?
Five item sets, one task set and 16 standalone items count, for 67 points. One more set and four standalone items are field-test questions that do not count toward the score.
How long is the LEAP Biology test?
Four hours in three timed sessions: 75 minutes, 90 minutes and 75 minutes. The second session holds the task set, which ends in an extended response scored on a 9-point rubric.
What is on the Biology LEAP test?
The Louisiana life science standards for high school: cells and body systems, photosynthesis and respiration, ecosystems, heredity, and natural selection and evolution. Questions ask students to investigate, weigh evidence and reason with models, and to do more than recall terms.
Is this the state's LEAP 2025 Biology practice test?
No. The department posts its own Biology practice test and answer key on its practice tests page; the button under the questions opens it. No question here is taken from it.