A crop plant is given a gene from a bacterium so that it resists an insect pest. What is this an example of?NHGRI Talking Glossary of Genomic and Genetic Terms, "Genetic Engineering". Outline: NES Biology (305) framework, competency 0003
A culture holds 3.0 × 10^6 bacteria per milliliter. A student dilutes it tenfold three times in a row. How many bacteria per milliliter are in the last tube?Worked arithmetic. The skill is listed in the NES Biology (305) framework: "Apply basic mathematical procedures and scientific notation", competency 0001
A food chain, a burning log and a falling rock can all be described with one principle shared by biology, chemistry and physics. Which principle is it?U.S. Energy Information Administration, Energy Explained, "Laws of energy". Outline: NES Biology (305) framework, competency 0002
A forensic lab recovers only a trace of DNA from a sample. Which technique makes millions of copies of one chosen segment so that it can be studied?NHGRI Talking Glossary of Genomic and Genetic Terms, "Polymerase Chain Reaction (PCR)". Outline: NES Biology (305) framework, competency 0003
Show all 45 questions (41 more)
Nature of science, continued
A study finds that children who eat breakfast score higher on tests. Family income is related both to eating breakfast and to test scores. What is family income in this study?Wikipedia, "Scientific control". Outline: NES Biology (305) framework, competency 0001
The genome editing tool CRISPR was adapted for the laboratory from a system found in nature. In which organisms does that system occur?NHGRI Talking Glossary of Genomic and Genetic Terms, "CRISPR". Outline: NES Biology (305) framework, competency 0003
In 1952 Stanley Miller passed an electric arc through a mixture of gases meant to stand for the atmosphere of the early Earth. What did the experiment produce?Wikipedia, "Miller–Urey experiment". Outline: NES Biology (305) framework, competency 0002
In a test of a new fertilizer, one set of plants gets the fertilizer and a second set, grown in the same light and soil, gets none. What is the purpose of the second set?Wikipedia, "Scientific control". Outline: NES Biology (305) framework, competency 0001
Which statement gives the difference between a hypothesis and a theory in science?Understanding Science (University of California Museum of Paleontology), "Science at multiple levels". Outline: NES Biology (305) framework, competency 0002
Biochemistry and cell biology 6
A cell in the pancreas makes a digestive protein and exports it. Which organelle processes and packages the protein on its way out of the cell?NHGRI Talking Glossary of Genomic and Genetic Terms, "Golgi Body". Outline: NES Biology (305) framework, competency 0005
A cell that is damaged beyond repair can destroy itself by apoptosis. Which organelle, filled with digestive enzymes, helps it to do so?NHGRI Talking Glossary of Genomic and Genetic Terms, "Lysosome". Outline: NES Biology (305) framework, competency 0005
An enzyme is a biological catalyst. How does a catalyst make a reaction go faster?Wikipedia, "Catalysis". Outline: NES Biology (305) framework, competency 0004
Some amino acids cannot be made in the body and must come from the diet. What are these amino acids called?NHGRI Talking Glossary of Genomic and Genetic Terms, "Amino Acids". Outline: NES Biology (305) framework, competency 0004
What do the light-dependent reactions of photosynthesis make for use in the reactions that build carbohydrates?Wikipedia, "Photosynthesis". Outline: NES Biology (305) framework, competency 0005
Which base takes the place of thymine when a cell builds RNA instead of DNA?NHGRI Talking Glossary of Genomic and Genetic Terms, "Nucleotide". Outline: NES Biology (305) framework, competency 0004
Genetics and evolution 12
A recessive trait carried on the X chromosome shows up far more often in males than in females. Why?NHGRI Talking Glossary of Genomic and Genetic Terms, "X-Linked". Outline: NES Biology (305) framework, competency 0007
A researcher wants many copies of a gene. She splices it into a small circular DNA molecule that bacteria copy apart from their chromosome. What is that molecule called?NHGRI Talking Glossary of Genomic and Genetic Terms, "Plasmid". Outline: NES Biology (305) framework, competency 0006
A river changes course and splits a population of ground squirrels in two. Over many generations the two groups become separate species. Which kind of speciation is this?Wikipedia, "Allopatric speciation". Outline: NES Biology (305) framework, competency 0008
A trait is passed from an affected mother to all of her children and is never passed on by an affected father. Where is the gene most likely found?NHGRI Talking Glossary of Genomic and Genetic Terms, "Mitochondrial DNA". Outline: NES Biology (305) framework, competency 0007
Before a gene can be transcribed, RNA polymerase binds to a region of DNA upstream of the gene. What is that region called?NHGRI Talking Glossary of Genomic and Genetic Terms, "Promoter". Outline: NES Biology (305) framework, competency 0006
In a population in Hardy-Weinberg equilibrium, allele A has a frequency of 0.6 and allele a has a frequency of 0.4. What is the expected frequency of heterozygotes?Wikipedia, "Hardy–Weinberg principle". Outline: NES Biology (305) framework, competency 0008
In cladistics, which kind of evidence is used to group organisms into a clade?Wikipedia, "Cladistics". Outline: NES Biology (305) framework, competency 0009
In which kind of population are the random changes in allele frequency called genetic drift strongest?NHGRI Talking Glossary of Genomic and Genetic Terms, "Genetic Drift". Outline: NES Biology (305) framework, competency 0008
Mitochondria have their own circular chromosome and reproduce by binary fission. Which explanation of their origin does this evidence support?Wikipedia, "Symbiogenesis". Outline: NES Biology (305) framework, competency 0009
Two parents are both carriers of the same autosomal recessive trait. What is the chance that a given child shows the trait?NHGRI Talking Glossary of Genomic and Genetic Terms, "Carrier". Outline: NES Biology (305) framework, competency 0007
Which change to a gene is a frameshift mutation?NHGRI Talking Glossary of Genomic and Genetic Terms, "Frameshift Mutation". Outline: NES Biology (305) framework, competency 0006
The wing of a bat, the flipper of a whale and the arm of a primate are built on the same set of bones. What does evolutionary biology call such structures?Wikipedia, "Homology (biology)". Outline: NES Biology (305) framework, competency 0009
Biological unity and diversity 9
Bacteria at a deep-sea vent produce food where no sunlight reaches. Which process do they use?NOAA Ocean Exploration, "What is the difference between photosynthesis and chemosynthesis?". Outline: NES Biology (305) framework, competency 0011
How does a fungus growing on a fallen log take in its food?Wikipedia, "Fungus". Outline: NES Biology (305) framework, competency 0011
In a nephron of the kidney, the glomerulus filters the blood. What does the tubule do?National Institute of Diabetes and Digestive and Kidney Diseases, "Your Kidneys & How They Work". Outline: NES Biology (305) framework, competency 0012
In the life cycle of a plant, which phase is diploid?Wikipedia, "Alternation of generations". Outline: NES Biology (305) framework, competency 0010
On a hot, dry afternoon a leaf narrows its stomata and loses less water. Which cells control the size of each opening?Wikipedia, "Stoma". Outline: NES Biology (305) framework, competency 0011
Which component of the immune system circulates in the blood, recognizes a foreign substance and neutralizes it?NHGRI Talking Glossary of Genomic and Genetic Terms, "Antibody". Outline: NES Biology (305) framework, competency 0012
Which feature of their cell walls sets fungi apart from plants?Wikipedia, "Fungus". Outline: NES Biology (305) framework, competency 0010
Which valve separates the right atrium of the heart from the right ventricle?National Heart, Lung, and Blood Institute, "How Blood Flows through the Heart". Outline: NES Biology (305) framework, competency 0012
Why can a virus not reproduce outside a host cell?NHGRI Talking Glossary of Genomic and Genetic Terms, "Virus". Outline: NES Biology (305) framework, competency 0010
Ecology and environment 9
A deer population grows quickly, then levels off near 400 animals year after year. What does the number 400 represent for this habitat?Wikipedia, "Carrying capacity". Outline: NES Biology (305) framework, competency 0013
Acid rain damages forests and lakes far from its source. Which two pollutants, emitted into the air, cause it?U.S. Environmental Protection Agency, "What is Acid Rain?". Outline: NES Biology (305) framework, competency 0015
An oyster releases millions of eggs, and nearly all of the young die within days. Which survivorship curve fits this species?Wikipedia, "Survivorship curve". Outline: NES Biology (305) framework, competency 0013
Chlorine released by chlorofluorocarbons thins the ozone layer in the stratosphere. Which change at Earth's surface follows?U.S. Environmental Protection Agency, "Basic Ozone Layer Science". Outline: NES Biology (305) framework, competency 0015
The grass in a field stores 10,000 units of energy. About how much of that energy ends up as tissue in the rabbits that eat the grass?Wikipedia, "Trophic level". Outline: NES Biology (305) framework, competency 0014
Most of the nitrogen gas that enters food webs is first converted to a usable form by what?Wikipedia, "Nitrogen cycle". Outline: NES Biology (305) framework, competency 0014
What is the main cause of ocean acidification?NOAA National Ocean Service, Ocean Facts, "What is Ocean Acidification?". Outline: NES Biology (305) framework, competency 0015
When a species of starfish is removed from a rocky shore, mussels take over and many other species vanish. What does this make the starfish?Wikipedia, "Keystone species". Outline: NES Biology (305) framework, competency 0013
Which feature defines the tundra biome and helps explain why it has almost no trees?NASA Earth Observatory, Mission: Biomes, "Tundra". Outline: NES Biology (305) framework, competency 0014
How this list was compiled: Our own questions, written to the test framework for NES Biology, test 305, read 2026-10-09 on the National Evaluation Series site (https://www.nestest.com/static/docs/NES_Framework_305.pdf; test page https://www.nestest.com/test/305): Nature of Science (competencies 0001 to 0003, 20%), Biochemistry and Cell Biology (0004 to 0005, 13%), Genetics and Evolution (0006 to 0009, 27%), Biological Unity and Diversity (0010 to 0012, 20%) and Ecology and Environment (0013 to 0015, 20%). The bank holds 3 questions for each of the 15 competencies. Every fact was read on 2026-10-09 in the public page the question names: the NHGRI Talking Glossary (genome.gov), NIDDK, NHLBI, NOAA, EPA, NASA Earth Observatory, the Energy Information Administration, Understanding Science (University of California Museum of Paleontology) and Wikipedia. One question is arithmetic worked in its explanation. Licence: Questions, choices and explanations are original work of this site.
How it works
This free NES Biology practice test has 45 questions of our own, three for each of the 15 competencies of test 305. It is unofficial and not affiliated with Pearson, which owns the National Evaluation Series.
Read the full guide
Study guide: the five domains
By the framework read October 9, 2026, NES Biology (305) weights Nature of Science 20%, Biochemistry and Cell Biology 13%, Genetics and Evolution 27%, Biological Unity and Diversity 20%, and Ecology and Environment 20%.
How the 45 questions are spread
Nine on the nature of science, six on biochemistry and cells, twelve on genetics and evolution, nine on unity and diversity, and nine on ecology. A timed run gives 54 minutes, the real 1.2 minutes a question.
Where the answers come from
Each explanation names the public page its fact was read in: the NHGRI genetics glossary, NIDDK, NHLBI, NOAA, EPA, NASA Earth Observatory, or the named Wikipedia article.
Genetics and Evolution is the largest domain, with four of the 15 competencies, so start there if time is short.
The only reference the test page lists is an on-screen calculator, so expect Hardy-Weinberg and dilution arithmetic with no formula sheet.
Questions and answers
Is this NES Biology practice test the real exam?
No. The 45 questions here are our own, each built on one competency of the 305 framework and one public page, which its explanation names. No item of the real test, the study guide or the paid practice test was used.
How many questions are on the NES Biology test?
Test 305 asks 150 multiple-choice questions in 3 hours of testing. Add 15 minutes for the tutorial and nondisclosure agreement, and the appointment runs 3 hours and 15 minutes.
What is the passing score for NES Biology?
220 is the national benchmark on the test page, which also links the passing scores of Arizona, Washington and Wisconsin, since a state may set its own. This page reports the number right, which does not convert to that scale.
Is NES Biology 316 the same test as 305?
No. Test 316 is the redeveloped Biology test, first given April 17, 2023, with 100 multiple-choice questions, and the older 305 remains available. The questions here follow 305, so ask your state's licensing agency which code it accepts.