I85PREP
⌘ K
FTCE Biology 6-12 study materials
FTCE Biology 6-12 study resources

FTCE Biology 6-12 practice questions

One question at a time. Build your FTCE Biology 6-12 understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Nature of Science

In scientific research, a hypothesis is best described as which of the following?

  1. a summary of observations recorded during an investigation
  2. an untested guess that cannot be evaluated with data
  3. a broad explanation that is supported by a large body of evidence
  4. a testable prediction of what will happen in an experiment Correct answer.

Explanation

A hypothesis is a proposed, testable explanation or prediction that can be judged against evidence. A broad, heavily supported explanation is a scientific theory, and a claim that cannot be tested lies outside the scope of science.

Question 2Nature of Science

A researcher tests a new fertilizer by giving it to one set of plants and giving no fertilizer to a second, otherwise identical set. The second set is best described as which of the following?

  1. the dependent variable
  2. the control group Correct answer.
  3. an additional replication
  4. the experimental group

Explanation

The control group is handled identically except that it does not receive the treatment, so any difference can be credited to the treatment. The fertilized set is the experimental group.

Question 3Nature of Science

Students investigate how light intensity affects the rate of photosynthesis in pond weed while holding temperature and carbon dioxide constant. The independent variable is which of the following?

  1. the number of leaves used
  2. the rate of photosynthesis
  3. the light intensity Correct answer.
  4. the temperature of the water

Explanation

The independent variable is the factor the investigator deliberately changes, which here is light intensity. The rate of photosynthesis is measured as the outcome, so it is the dependent variable.

Question 4Nature of Science

Which of the following is the SI base unit for mass?

  1. the liter
  2. the kilogram Correct answer.
  3. the newton
  4. the gram

Explanation

The kilogram is the SI base unit for mass, while the gram is a decimal fraction of it. The liter measures volume and the newton measures force.

Question 5Nature of Science

A scientist records that a culture dish contains 42 bacterial colonies. This statement is best classified as which of the following?

  1. a prediction of future growth
  2. an inference about the bacteria
  3. a qualitative observation
  4. a quantitative observation Correct answer.

Explanation

An observation that involves counting or measuring produces numerical data and is therefore quantitative. Qualitative observations describe qualities such as color or shape without numbers.

Question 6Nature of Science

A researcher repeats an experiment five times and obtains similar results each time. Replication most directly increases which of the following?

  1. the reliability of the results Correct answer.
  2. the size of the effect measured
  3. the number of variables tested
  4. the need for a control group

Explanation

Repeated trials allow random variation to average out and reveal whether results are consistent, which increases reliability. Replication does not change the variables studied or enlarge the effect itself.

Question 7Nature of Science

A balance gives readings of 5.00 g, 5.01 g, and 4.99 g for a standard sample whose true mass is 5.30 g. These measurements are best described as which of the following?

  1. precise but not accurate Correct answer.
  2. accurate but not precise
  3. neither accurate nor precise
  4. both accurate and precise

Explanation

Precision describes how closely repeated measurements agree with one another, and these readings cluster tightly. Accuracy describes closeness to the true value, and all three readings fall far below 5.30 g.

Question 8Nature of Science

What is the main purpose of peer review before a scientific paper is published?

  1. to guarantee that the reported results are correct
  2. to allow the editor to revise the data as needed
  3. to remove the need for other scientists to repeat the study
  4. to require evaluation by independent experts before publication Correct answer.

Explanation

Peer review sends a manuscript to qualified specialists who judge its methods, evidence, and reasoning before publication. It improves quality but cannot guarantee correctness and does not replace replication.

Question 9Nature of Science

Which practice is safest when heating a liquid in a test tube over a flame?

  1. filling the tube completely to the top
  2. holding the tube with bare fingers close to the flame
  3. stoppering the tube tightly before heating
  4. pointing the tube away from yourself and others Correct answer.

Explanation

Heated liquids can boil over or eject suddenly, so the mouth of the tube must be aimed away from people. Tubes should be partly filled, held with a clamp or holder, and left open to prevent pressure buildup.

Question 10Nature of Science

A student records the height of a bean plant every day for six weeks. Which display best shows how the height changes over time?

  1. a line graph Correct answer.
  2. a bar graph
  3. a pie chart
  4. a diagram of the plant's parts

Explanation

A line graph plots a continuous variable against time and makes trends visible. Pie charts show parts of a whole, and bar graphs compare separate categories rather than continuous change.

Question 11Nature of Science

Surveys show that sales of ice cream and the number of drownings both rise during the summer. Which explanation is most consistent with scientific reasoning?

  1. a third factor, such as warm weather, influences both Correct answer.
  2. the relationship is a meaningless coincidence with no cause at all
  3. eating ice cream directly causes drowning
  4. drowning deaths cause an increase in ice cream sales

Explanation

A correlation between two variables does not by itself establish that one causes the other. A third variable, warm weather, plausibly increases both swimming and ice cream consumption.

Question 12Nature of Science

The length 0.00045 m is written in scientific notation as which of the following?

  1. 4.5 x 10^-4 m Correct answer.
  2. 45 x 10^-3 m
  3. 4.5 x 10^-5 m
  4. 4.5 x 10^4 m

Explanation

Scientific notation writes a number as a coefficient between 1 and 10 multiplied by a power of ten. Shifting the decimal point four places to the right gives 4.5, so the exponent is negative four.

Question 13Nature of Science

A compound light microscope has a 10x ocular lens and a 45x objective lens in use. What is the total magnification?

  1. 450x Correct answer.
  2. 45x
  3. 4,500x
  4. 55x

Explanation

Total magnification is the product of the ocular and objective magnifications, so 10 x 45 = 450. Adding the two values instead of multiplying them is a common error.

Question 14Nature of Science

How many significant figures are in the measurement 0.02030 g?

  1. 3
  2. 4 Correct answer.
  3. 6
  4. 5

Explanation

Leading zeros are never significant, so the digits 2, 0, 3, and the trailing zero after the 3 all count, giving four. A trailing zero counts only when a decimal point is present in the number.

Question 15Nature of Science

Why are double-blind procedures used in clinical trials?

  1. to increase the total number of participants in the study
  2. to make the treatment more powerful than a placebo
  3. to reduce the influence of expectations held by researchers and participants Correct answer.
  4. to remove the need for a control group

Explanation

In a double-blind design neither the participants nor the researchers who interact with them know who receives the treatment, which limits expectation effects and bias. A control group is still required, and blinding does not change how a treatment acts biologically.

Question 16Nature of Science

A researcher reports that a new supplement improves memory. Which feature of the study would most seriously weaken confidence in that conclusion?

  1. participants chose whether to receive the supplement or the placebo Correct answer.
  2. the study included 120 participants of similar age
  3. the participants' ages ranged from 20 to 30 years
  4. the memory test was administered by a research assistant

Explanation

Self-selection lets the groups differ in ways unrelated to the supplement, such as motivation or baseline memory, creating a confounding variable. Random assignment is needed so the groups start out comparable.

Question 17Nature of Science

A geologist states that a particular rock layer is about 65 million years old. This statement is best classified as which of the following?

  1. a controlled experiment
  2. a direct observation
  3. a measurement error
  4. an inference Correct answer.

Explanation

The age is not observed directly but is concluded from evidence such as radiometric data and stratigraphy, which makes it an inference. Observations are limited to what can be perceived or measured directly.

Question 18Nature of Science

In an experiment, enzyme activity was measured at five pH values: pH 4 gave 12 units, pH 5 gave 28 units, pH 6 gave 45 units, pH 7 gave 30 units, and pH 8 gave 10 units. Which pH is the optimum for this enzyme?

  1. pH 7
  2. pH 8
  3. pH 6 Correct answer.
  4. pH 4

Explanation

The optimum is the condition producing the highest measured activity, which is 45 units at pH 6. Activity falls on either side of that peak, which is the expected pattern around an optimal pH.

Question 19Nature of Science

A volume of 250 mL is equal to which of the following?

  1. 0.25 L Correct answer.
  2. 25 L
  3. 0.025 L
  4. 2.5 L

Explanation

There are 1,000 milliliters in a liter, so dividing 250 by 1,000 gives 0.25 L. Converting milliliters to liters requires moving the decimal point three places to the left.

Question 20Nature of Science

A student measures the rate of respiration in yeast by counting the bubbles released per minute at several temperatures. Which statement is the operational definition of the dependent variable?

  1. the amount of sugar added to the suspension
  2. the temperature of the yeast suspension
  3. the number of bubbles counted per minute Correct answer.
  4. the rate of cellular respiration

Explanation

An operational definition states exactly how a variable is measured in the investigation. Here respiration is defined operationally as bubbles counted per minute, while temperature and sugar are controlled or manipulated factors.

Question 21Nature of Science

Which characteristic is essential for a claim to be considered scientific?

  1. it agrees with what most people believe to be true
  2. it cannot be measured with available instruments
  3. it can be tested by observation or experiment Correct answer.
  4. it is supported by a well-known authority in the field

Explanation

Scientific claims must be empirically testable, meaning evidence could support or contradict them. Appeals to authority, popular opinion, or untestability do not establish scientific validity.

Question 22Nature of Science

A set of enzyme rate measurements contains one value much larger than all the others. Which statistic best represents the typical value in the data set?

  1. the mean
  2. the range
  3. the mode
  4. the median Correct answer.

Explanation

The median is the middle value and is resistant to extreme scores, so it represents a typical value better when outliers are present. The mean is pulled toward the outlier, and the range describes spread.

Question 23Nature of Science

A balance is mis-calibrated and reads 0.8 g too high every time a sample is weighed. This is best described as which of the following?

  1. sampling error
  2. observer bias
  3. systematic error Correct answer.
  4. random error

Explanation

Systematic error shifts every measurement in the same direction by a consistent amount, as a miscalibrated instrument does. Random error instead scatters measurements unpredictably around the true value.

Question 24Nature of Science

Which practice is most consistent with scientific integrity?

  1. sharing data only with the laboratory that collected them
  2. reporting all trials, including those that did not support the hypothesis Correct answer.
  3. publishing only the trials that produced significant results
  4. adjusting outlying data points so the trend is clearer

Explanation

Scientific integrity requires complete and honest reporting, including results that fail to support the hypothesis, because selective reporting distorts the evidence base. Data must not be altered to produce a desired trend.

Question 25Nature of Science

Scientists use computer models to predict how a fish population will change over time. Which statement identifies a fundamental limitation of this approach?

  1. it always requires fewer observations than a field study
  2. its predictions depend on the assumptions built into the model Correct answer.
  3. it can only be used after field data have been discarded
  4. it produces results that cannot be repeated by anyone

Explanation

A model is a simplified representation, so its output is only as trustworthy as the assumptions and parameters entered into it. Models must also be checked against real observations before their predictions are accepted.

Question 26Nature of Science

Which statement best describes the roles of a scientific theory and a scientific law?

  1. A law is more certain than a theory because laws are proven.
  2. A theory becomes a law after enough supporting evidence is collected.
  3. A theory explains a pattern; a law describes the pattern. Correct answer.
  4. Both theories and laws are educated guesses until proven correct.

Explanation

A scientific theory is a well-supported explanation for why something happens, while a scientific law describes a consistent relationship or pattern. Theories and laws serve different functions and one does not turn into the other as evidence accumulates.

Question 27Nature of Science

A student predicts that bean plants given more light will grow taller. She places ten plants in full sunlight and ten plants in shade and measures their heights after three weeks. What is the independent variable?

  1. Number of plants in each group
  2. Type of soil used for the plants
  3. Height of the plants after three weeks
  4. Amount of light the plants receive Correct answer.

Explanation

The independent variable is the factor the experimenter deliberately changes, which here is the amount of light. Plant height is the dependent variable because it is measured as a response, while the number of plants and soil type are held constant.

Question 28Nature of Science

In an experiment testing a new fertilizer, one group of plants receives no fertilizer. What is the main reason for including this group?

  1. It guarantees that all plants will grow.
  2. It tests a second kind of fertilizer.
  3. It increases the total number of plants.
  4. It provides a baseline for comparison. Correct answer.

Explanation

The untreated group serves as a control, providing a baseline against which the fertilized group can be compared. Without this baseline, any change could not be attributed to the fertilizer rather than to other conditions.

Question 29Nature of Science

A geologist sees shells in a rock layer and states that the area was once covered by water. Which statement is the inference?

  1. The rock layer contains shells.
  2. The area was once covered by water. Correct answer.
  3. The sample was collected at a depth of 2 m.
  4. The layer is 30 cm thick.

Explanation

An inference is an interpretation drawn from observations rather than something directly observed. The presence of shells is observed, while the conclusion about past water coverage is an explanation based on that observation.

Question 30Nature of Science

A researcher estimates the average height of trees in a large forest by measuring only the trees beside a road. What is the main problem with this approach?

  1. Tree height cannot be measured with accuracy.
  2. Trees in a forest grow at different rates.
  3. Roadside trees may not represent the forest. Correct answer.
  4. The sample size is far too large for the analysis.

Explanation

A sample must represent the whole population for estimates to be valid, and roadside trees may differ systematically from trees in the forest interior. Choosing subjects based on convenience rather than random selection introduces sampling bias.

Question 31Nature of Science

A clinical trial finds no statistically significant difference between a new drug and a placebo. Which conclusion is most appropriate?

  1. The drug definitely has no effect on any patient.
  2. The study found no evidence the drug beats placebo. Correct answer.
  3. The drug should be approved for immediate clinical use.
  4. The placebo must have caused any improvement seen.

Explanation

Failing to find a statistically significant difference means the data do not provide evidence that the drug performs better than the placebo. It does not prove the drug has no effect, because a real effect could be too small or too variable to detect in that study.

Question 32Nature of Science

A student tests how different wavelengths of light affect the rate of oxygen production in pondweed. Which variable should be held constant?

  1. Number of trials performed
  2. Rate of oxygen production
  3. Wavelength of the light
  4. Water temperature Correct answer.

Explanation

In a controlled experiment, all variables except the independent variable must be kept constant so that any effect can be attributed to the factor being tested. Water temperature could influence oxygen production, so it should be held constant across trials.

Question 33Nature of Science

Why does an experiment that supports a hypothesis fail to prove it true?

  1. Experiments are always too poorly designed to settle questions.
  2. Hypotheses cannot be tested by observation or experiment.
  3. Alternative explanations may still remain possible. Correct answer.
  4. Proof is only possible in the physical sciences, not biology.

Explanation

Scientific hypotheses are supported rather than proven, because observations consistent with a hypothesis do not eliminate every other possible explanation. Confidence grows when multiple independent lines of evidence support the same explanation.

Question 34Nature of Science

Scientists once accepted that stomach ulcers were caused mainly by stress, but later research showed that a bacterium plays a major role. This change best illustrates which characteristic of science?

  1. Older scientific explanations are never useful to modern scientists.
  2. Medical findings are not considered scientific knowledge.
  3. Scientific laws cannot be changed once they are established.
  4. Scientific knowledge can be revised as new evidence appears. Correct answer.

Explanation

Science is self-correcting: explanations are modified or replaced when new and reliable evidence conflicts with them. The ulcer case shows that accepted ideas can change as investigations produce better evidence.

Question 35Molecular and Cellular Biology

Which property of water allows insects such as water striders to move across the surface of a pond?

  1. A low specific heat capacity of water
  2. Surface tension created by hydrogen bonding Correct answer.
  3. The greater density of ice compared with liquid water
  4. The nonpolar nature of water molecules

Explanation

Water molecules form extensive hydrogen bonds with one another, and at an air-water interface these cohesive forces produce surface tension. That tension resists being broken and can support the weight of small organisms. The other listed properties exist but do not create a supporting surface film.

Question 36Molecular and Cellular Biology

Which organelle contains hydrolytic enzymes used to break down worn-out organelles and ingested macromolecules?

  1. The peroxisome
  2. The lysosome Correct answer.
  3. The smooth endoplasmic reticulum
  4. The Golgi apparatus

Explanation

Lysosomes are acidic vesicles that house hydrolytic enzymes capable of digesting proteins, lipids, nucleic acids, and carbohydrates. They receive these enzymes from the Golgi and fuse with targets such as damaged organelles or phagosomes.

Question 37Molecular and Cellular Biology

A distinguishing feature of prokaryotic cells is that they

  1. carry out oxidative phosphorylation in mitochondria
  2. package proteins in the Golgi apparatus
  3. lack a membrane-bound nucleus Correct answer.
  4. contain membrane-bound nuclei

Explanation

Prokaryotes keep their genetic material in a nucleoid region that is not enclosed by a nuclear envelope, which is the defining structural difference from eukaryotes. They also lack the membrane-bound organelles listed in the other options.

Question 38Molecular and Cellular Biology

The energy released when ATP is hydrolyzed to ADP and Pi comes most directly from

  1. cleavage of the terminal phosphoanhydride bond Correct answer.
  2. the reduction of the adenine ring
  3. the transfer of an electron to oxygen
  4. a decrease in cellular free energy

Explanation

ATP stores usable energy chiefly in the phosphoanhydride bonds between its phosphate groups. Hydrolysis of the terminal bond releases free energy that can be coupled to endergonic cellular work.

Question 39Molecular and Cellular Biology

A solution with a pH of 3 differs from a solution with a pH of 6 in that it has

  1. three times the hydrogen ion concentration
  2. one-third the hydrogen ion concentration
  3. 1,000 times the hydrogen ion concentration Correct answer.
  4. twice the hydrogen ion concentration

Explanation

The pH scale is logarithmic, so each unit represents a tenfold change in hydrogen ion concentration. A difference of three pH units therefore corresponds to a factor of 10 x 10 x 10, or 1,000.

Question 40Molecular and Cellular Biology

A red blood cell is placed in a hypertonic saline solution. What will happen to the cell?

  1. It will swell and burst
  2. It will stay the same size
  3. It will absorb salt until it is isotonic
  4. It will lose water and shrink Correct answer.

Explanation

In a hypertonic environment the solute concentration outside the cell is higher than inside, so water moves out by osmosis. Loss of water causes the cell to shrink, a process called crenation in red blood cells.

Question 41Molecular and Cellular Biology

Which pairing of a biological macromolecule with its monomer is correct?

  1. Lipid - nucleotide
  2. Nucleic acid - amino acid
  3. Protein - monosaccharide
  4. Carbohydrate - monosaccharide Correct answer.

Explanation

Carbohydrates such as starch and cellulose are polymers built from monosaccharide units joined by glycosidic bonds. Each macromolecule class has its own characteristic monomer type.

Question 42Molecular and Cellular Biology

During which phase of mitosis are chromosomes aligned along the cell equator before sister chromatids separate?

  1. Anaphase
  2. Telophase
  3. Metaphase Correct answer.
  4. Prophase

Explanation

During metaphase, spindle fibers attach to kinetochores and position the duplicated chromosomes along the metaphase plate at the cell equator. Separation of chromatids occurs afterward, in anaphase.

Question 43Molecular and Cellular Biology

A competitive inhibitor slows an enzyme-catalyzed reaction. Which change would most effectively restore the reaction rate?

  1. Increasing the enzyme concentration
  2. Raising the substrate concentration Correct answer.
  3. Adding a noncompetitive inhibitor
  4. Lowering the temperature of the reaction

Explanation

A competitive inhibitor binds the active site reversibly, so its effect depends on the ratio of inhibitor to substrate. Adding more substrate outcompetes the inhibitor for active sites and restores the maximal rate.

Question 44Molecular and Cellular Biology

Glycolysis in a eukaryotic cell occurs in the cytosol and yields a net gain of which products per molecule of glucose?

  1. 2 ATP and 2 NADH Correct answer.
  2. 36 ATP and 6 CO2
  3. 2 ATP and 4 NADH
  4. 4 ATP and 2 NADH

Explanation

Glycolysis produces 4 ATP by substrate-level phosphorylation but consumes 2 ATP during the investment phase, for a net gain of 2 ATP. Two molecules of NAD+ are also reduced to NADH per glucose.

Question 45Molecular and Cellular Biology

Which products are released during the citric acid cycle for each molecule of glucose processed?

  1. Only ATP and NADH
  2. CO2, NADH, FADH2, and ATP Correct answer.
  3. CO2 and O2
  4. Pyruvate, lactate, and NAD+ from fermentation

Explanation

Each turn of the citric acid cycle releases two carbons as CO2 and reduces NAD+ and FAD to NADH and FADH2, with one ATP (or GTP) formed by substrate-level phosphorylation. Because two acetyl-CoA enter per glucose, these yields are doubled per glucose.

Question 46Molecular and Cellular Biology

Which products of the light-dependent reactions are used directly in the Calvin cycle?

  1. ADP, Pi, and NAD+
  2. ATP and NADPH Correct answer.
  3. NADH and FADH2
  4. O2 and glucose

Explanation

The light reactions generate ATP by photophosphorylation and reduce NADP+ to NADPH. The Calvin cycle then spends that ATP and NADPH to fix CO2 into carbohydrate.

Question 47Molecular and Cellular Biology

During DNA replication, which enzyme joins Okazaki fragments by forming phosphodiester bonds between them?

  1. Primase
  2. DNA ligase Correct answer.
  3. DNA polymerase III
  4. DNA helicase

Explanation

DNA ligase seals the single-strand nicks left between adjacent Okazaki fragments on the lagging strand. It catalyzes formation of the final phosphodiester bond that completes the sugar-phosphate backbone.

Question 48Molecular and Cellular Biology

Which statement accurately describes the role of a promoter in transcription?

  1. It is the DNA site where RNA polymerase binds Correct answer.
  2. It encodes the amino acid sequence of the protein
  3. It is the site where introns are removed from mRNA
  4. It signals the ribosome to stop translation

Explanation

A promoter is a DNA sequence upstream of a gene that is recognized by RNA polymerase and its transcription factors. Binding there positions the polymerase to begin transcription at the correct start site.

Question 49Molecular and Cellular Biology

During translation, the anticodon of a tRNA molecule pairs with

  1. the small ribosomal subunit
  2. the growing polypeptide chain
  3. a complementary codon on mRNA Correct answer.
  4. a complementary sequence on rRNA

Explanation

Anticodons are complementary to mRNA codons, and base pairing between them ensures the correct amino acid is delivered to the ribosome. This antiparallel pairing follows standard Watson-Crick rules.

Question 50Molecular and Cellular Biology

The genetic code is described as degenerate because

  1. the code differs between prokaryotes and eukaryotes
  2. some codons code for more than one amino acid
  3. several codons can specify the same amino acid Correct answer.
  4. most amino acids are encoded by only one codon

Explanation

Degeneracy means that more than one codon can specify the same amino acid, which is possible because there are 64 codons for only 20 amino acids. This redundancy reduces the impact of some point mutations.