Free TEAS 7 Science Practice Test 8 — 30 Questions With Full Explanations

Question 1. Anatomy & Physiology easy

Which organ serves as the storage site for the bile that the liver has produced?

• A. Gallbladder (correct)
• B. Pancreas
• C. Stomach
• D. Spleen

Explanation: The gallbladder is a small sac beneath the liver that stores and concentrates bile between meals. The pancreas secretes digestive enzymes and bicarbonate, the stomach digests proteins, and the spleen filters blood; none of these store bile.

Question 2. Anatomy & Physiology medium

Which set of three small bones lies within the middle ear and forms a chain linking the tympanic membrane to the oval window?

• A. Utricle, saccule, and ampullae
• B. Malleus, incus, and stapes (correct)
• C. Tympanic membrane, oval window, and round window
• D. Cochlea, semicircular canals, and vestibule

Explanation: Sound waves vibrate the tympanic membrane, and the malleus, incus, and stapes transmit those vibrations across the middle ear to the oval window. The cochlea, vestibule, and semicircular canals are inner ear structures, and the utricle, saccule, and ampullae are equilibrium receptors, not middle ear bones.

Question 3. Anatomy & Physiology easy

Which cells of the epidermis produce melanin, the pigment that gives skin its color and helps shield cells from ultraviolet radiation?

• A. Keratinocytes
• B. Langerhans cells
• C. Melanocytes (correct)
• D. Merkel cells

Explanation: Melanocytes are pigment-producing cells in the deepest layer of the epidermis. Keratinocytes produce keratin, Langerhans cells are immune cells of the skin, and Merkel cells are touch receptors, so none of them synthesize the melanin that colors skin and absorbs ultraviolet light.

Question 4. Anatomy & Physiology medium

Which arteries branch directly from the aorta to supply the muscular wall of the heart with blood?

• A. Pulmonary arteries
• B. Carotid arteries
• C. Renal arteries
• D. Coronary arteries (correct)

Explanation: The coronary arteries branch from the aorta and deliver oxygenated blood to the myocardium, the heart's own muscle. The pulmonary arteries carry blood to the lungs, the carotid arteries serve the brain, and the renal arteries serve the kidneys, not the heart muscle itself.

Question 5. Anatomy & Physiology medium

Which paired folds of tissue in the larynx vibrate as exhaled air passes over them to produce the voice?

• A. Epiglottis
• B. Uvula
• C. Vocal cords (correct)
• D. Palatine tonsils

Explanation: The vocal cords, or vocal folds, are paired elastic folds in the larynx that vibrate as exhaled air passes between them, producing sound. The epiglottis guards the airway during swallowing, the uvula hangs from the soft palate, and the tonsils are lymphoid tissue, so none vibrate to create voice.

Question 6. Anatomy & Physiology medium

Which brain region directly controls the pituitary gland and thereby coordinates many of the body's hormonal signals?

• A. Hypothalamus (correct)
• B. Cerebellum
• C. Medulla oblongata
• D. Corpus callosum

Explanation: The hypothalamus, located above the pituitary, links the nervous and endocrine systems: it secretes releasing and inhibiting hormones that control the anterior pituitary and acts as the body's thermostat. The cerebellum coordinates movement, the medulla sets breathing and heart rhythm, and the corpus callosum connects the hemispheres.

Question 7. Anatomy & Physiology medium

Which large vein delivers blood from the digestive organs directly to the liver for processing before the blood continues toward the heart?

• A. Pulmonary vein
• B. Inferior vena cava
• C. Aorta
• D. Hepatic portal vein (correct)

Explanation: The hepatic portal vein collects blood rich in absorbed nutrients from the stomach, intestines, pancreas, and spleen and delivers it to the liver, which processes and detoxifies the absorbed substances. The pulmonary vein, inferior vena cava, and aorta do not drain the digestive organs into the liver.

Question 8. Anatomy & Physiology medium

Which nutrient element is a required component of the diet because it is incorporated into the structure of the thyroid hormones T3 and T4?

• A. Iron
• B. Iodine (correct)
• C. Calcium
• D. Zinc

Explanation: Dietary iodine is an essential component of thyroxine (T4) and triiodothyronine (T3), the thyroid hormones that regulate metabolic rate. Iron is needed for hemoglobin, calcium for bones and muscle function, and zinc for enzymes, but none are incorporated into thyroid hormone molecules.

Question 9. Anatomy & Physiology medium

Which set of bones belongs to the axial skeleton?

• A. Humerus, radius, and ulna
• B. Skull, vertebral column, and rib cage (correct)
• C. Femur, tibia, and fibula
• D. Clavicle, scapula, and humerus

Explanation: The axial skeleton forms the body's central axis and consists of the skull, vertebral column, and rib cage. The humerus, radius, and ulna are the upper limb, and the femur, tibia, and fibula form the lower limb; the clavicle and scapula are the pectoral girdle, all parts of the appendicular skeleton.

Question 10. Anatomy & Physiology hard

Which plasma protein is the most abundant and is the main contributor to colloid osmotic pressure, helping to keep fluid within the bloodstream?

• A. Fibrinogen
• B. Immunoglobulin G
• C. Prothrombin
• D. Albumin (correct)

Explanation: Albumin is the most abundant plasma protein and is the chief contributor to colloid osmotic pressure, which pulls water back into capillaries and keeps fluid in the bloodstream. Fibrinogen and prothrombin are clotting factors, and immunoglobulin G is an antibody, so none primarily regulate fluid distribution.

Question 11. Anatomy & Physiology hard

On a normal electrocardiogram, which wave represents the depolarization of the atria just before they contract?

• A. P wave (correct)
• B. QRS complex
• C. T wave
• D. PR segment

Explanation: The P wave records the spread of depolarization through the atria and precedes atrial contraction. The QRS complex reflects ventricular depolarization, the T wave reflects ventricular repolarization, and the PR segment is a flat interval between atrial and ventricular activity.

Question 12. Anatomy & Physiology hard

The sound 'dup' in 'lub-dup' is generated chiefly by the snapping shut of which valves at the start of ventricular relaxation?

• A. Atrioventricular (tricuspid and mitral) valves
• B. Atrioventricular and semilunar valves together
• C. Semilunar (aortic and pulmonary) valves (correct)
• D. Chordae tendineae and papillary muscles

Explanation: The second heart sound occurs at the start of ventricular diastole when the aortic and pulmonary (semilunar) valves snap shut after blood ejection. The tricuspid and mitral (AV) valves produce the first sound, S1, while chordae tendineae anchor the AV valves rather than making the sound.

Question 13. Biology easy

Which polysaccharide is the main structural component of plant cell walls?

• A. Glycogen
• B. Chitin
• C. Starch
• D. Cellulose (correct)

Explanation: Cellulose is a polysaccharide of beta-glucose units that forms the tough structural fibers of plant cell walls. Glycogen is animal energy storage, starch is plant energy storage, and chitin strengthens fungal cell walls and arthropod exoskeletons, so none make up plant cell walls.

Question 14. Biology medium

Which process is the usual method by which bacteria reproduce?

• A. Mitosis
• B. Meiosis
• C. Binary fission (correct)
• D. Sporulation

Explanation: Binary fission is the asexual process in which a bacterial cell duplicates its DNA and divides into two genetically identical cells. Mitosis and meiosis occur in eukaryotic cells, and sporulation is a survival strategy used by some bacteria and fungi rather than the main bacterial reproductive method.

Question 15. Biology medium

What is the name of the orderly, genetically programmed process by which unwanted cells, such as those between the developing digits, die and are removed from the body?

• A. Necrosis
• B. Apoptosis (correct)
• C. Senescence
• D. Metastasis

Explanation: Apoptosis is programmed cell death, an orderly, energy-dependent process that sculpts structures such as the fingers and toes during development. Necrosis is accidental cell death from injury, senescence is growth arrest in aging cells, and metastasis is the spread of cancer, so none describe programmed removal.

Question 16. Biology medium

In genetics, what is the name for a change of a single base pair in the DNA sequence, for example one base substituted for a different base?

• A. Point mutation (correct)
• B. Chromosomal translocation
• C. Nondisjunction
• D. Crossing over

Explanation: A point mutation changes a single nucleotide base pair, such as substituting one base for another, and may alter one codon. Translocation moves a chromosome segment, nondisjunction produces abnormal chromosome numbers, and crossing over exchanges segments between homologous chromosomes during meiosis.

Question 17. Biology hard

In bacteria, which regulatory unit consists of a promoter, an operator, and the structural genes it controls, allowing several genes to be switched on or off together?

• A. Codon
• B. Promoter sequence
• C. Operon (correct)
• D. Exon

Explanation: An operon is a coordinated unit of bacterial gene expression containing a promoter, an operator, and the structural genes they regulate, so transcription can be switched on or off together. A codon is three mRNA bases, an exon is a coding mRNA segment, and these are not multicomponent regulatory units.

Question 18. Biology hard

Which theory proposes that mitochondria and chloroplasts originated from free-living prokaryotes that were engulfed by ancestral eukaryotic cells?

• A. Cell theory
• B. Germ theory
• C. Theory of natural selection
• D. Endosymbiotic theory (correct)

Explanation: The endosymbiotic theory holds that mitochondria and chloroplasts arose from ancient prokaryotes engulfed by a host cell, supported by their own DNA, double membranes, and bacterial-like ribosomes. Germ theory explains infectious disease and cell theory describes living things as cells, so neither explains organelle origins.

Question 19. Chemistry easy

Which substance forms free-moving ions when dissolved in water and therefore conducts an electric current well?

• A. Sodium chloride (table salt) (correct)
• B. Sucrose (table sugar)
• C. Ethanol
• D. Olive oil

Explanation: Sodium chloride is an ionic compound that dissociates fully into Na+ and Cl- ions in water, and these mobile ions conduct an electric current, making it a strong electrolyte. Sucrose and ethanol dissolve as neutral molecules and olive oil does not dissolve, so they do not conduct electricity.

Question 20. Chemistry medium

A solid block has a mass of 24.0 g and a volume of 8.0 mL. What is its density?

• A. 3.0 g/mL (correct)
• B. 0.33 g/mL
• C. 32 g/mL
• D. 192 g/mL

Explanation: Density equals mass divided by volume, so 24.0 g divided by 8.0 mL gives 3.0 g/mL. The value 0.33 g/mL comes from dividing volume by mass, and 32 or 192 g/mL come from adding or multiplying the two numbers instead of dividing them.

Question 21. Chemistry medium

Given that a neutral calcium atom has 20 electrons, how many electrons does its 2+ ion (Ca2+) contain?

• A. 20 electrons
• B. 22 electrons
• C. 40 electrons
• D. 18 electrons (correct)

Explanation: A neutral calcium atom has 20 electrons, matching its 20 protons. Losing two electrons to form Ca2+ leaves 18 electrons; 20 is the neutral count, 22 would be a 2- ion, and 40 is the mass number, which counts protons plus neutrons rather than electrons.

Question 22. Chemistry medium

One mole of H2SO4 reacts with 2 mol of NaOH as shown: H2SO4 + 2 NaOH -> Na2SO4 + 2 H2O. Using this ratio, what amount of NaOH, in moles, is needed to react fully with 0.5 mol of H2SO4?

• A. 1.0 mol (correct)
• B. 0.25 mol
• C. 0.5 mol
• D. 2.0 mol

Explanation: The balanced equation shows that 2 mol of NaOH reacts with 1 mol of H2SO4, so neutralizing 0.5 mol of acid requires twice that amount, 1.0 mol of NaOH. The values 0.25 and 0.5 mol would treat the ratio incorrectly, and 2.0 mol would be double the correct amount.

Question 23. Chemistry hard

At standard temperature and pressure (STP, 0 C and 1 atm), one mole of an ideal gas occupies what volume?

• A. 11.2 L
• B. 22.4 L (correct)
• C. 44.8 L
• D. 1.0 L

Explanation: At STP, one mole of any ideal gas occupies 22.4 L, a value derived from the ideal gas law. The 11.2 L figure is half a mole, 44.8 L is two moles, and 1.0 L is far smaller because gases expand to fill their container at standard conditions.

Question 24. Chemistry hard

In a 2.0 mol quantity of water (H2O), what is the total amount of hydrogen, expressed in moles?

• A. 2.0 mol
• B. 1.0 mol
• C. 4.0 mol (correct)
• D. 6.0 mol

Explanation: Each water molecule contains two hydrogen atoms, so 2.0 mol of water molecules contains 2.0 x 2 = 4.0 mol of hydrogen atoms. The value 2.0 mol counts molecules rather than atoms, 1.0 mol would be half the molecules, and 6.0 mol would treat each water as three hydrogens.

Question 25. Scientific Reasoning easy

Before a research article is published in a scientific journal, other experts in the same field evaluate its methods and conclusions. What is this process called?

• A. Peer review (correct)
• B. Replication
• C. Randomization
• D. Meta-analysis

Explanation: Peer review is the process in which independent experts in the same field evaluate a manuscript's methods, data, and reasoning before publication, helping to screen out flawed work. Replication repeats a study, randomization assigns subjects to groups, and meta-analysis combines results across studies.

Question 26. Scientific Reasoning easy

Each blood type in a population is to be displayed as a slice of a circle, with the size of each slice matching how common that blood type is. Which type of graph should the researchers use?

• A. Line graph
• B. Histogram
• C. Pie chart (correct)
• D. Scatter plot

Explanation: A pie chart shows each category as a slice of a circle, making it ideal for displaying parts of a whole such as percentages of blood types. A line graph shows trends over time, a scatter plot shows relationships between two variables, and a histogram shows the distribution of continuous data.

Question 27. Scientific Reasoning medium

In formal statistical testing, what is the claim made by the null hypothesis about the population under study?

• A. A prediction that the treatment will produce a large effect
• B. A prediction that no real effect or difference exists in the population (correct)
• C. A statement of the direction in which an effect should occur
• D. An explanation of the mechanism behind an observed effect

Explanation: The null hypothesis states that no real effect or difference exists in the population, and statistical tests calculate the probability of the data assuming it is true so it can be rejected. Predictions of effect size or direction describe alternative hypotheses, not the null.

Question 28. Scientific Reasoning medium

A research group publishes a striking finding from a single study. Which action by other scientists would most strengthen confidence that the result is real?

• A. Reanalyzing the original data with new statistics
• B. Publishing a commentary criticizing the methods
• C. Interviewing additional participants without changing the design
• D. An independent laboratory repeating the study and obtaining the same result (correct)

Explanation: Independent replication, repeating the experiment in another laboratory with fresh procedures and obtaining the same result, provides the strongest evidence that a finding is real rather than an artifact. Reanalyzing the original data, commenting on methods, or interviewing more subjects without a new experiment cannot rule out hidden errors.

Question 29. Scientific Reasoning hard

A medical trial fails to detect a benefit of a new treatment even though the treatment truly is effective. Which type of error has occurred?

• A. A type I error
• B. A type II error (correct)
• C. A placebo effect
• D. A sampling bias

Explanation: Failing to detect a real effect, concluding the drug does not work when it actually does, is a type II error, the mistake of accepting a false null hypothesis. A type I error is detecting an effect that is not real, a placebo effect is a response to an inert treatment, and sampling bias distorts who is studied.

Question 30. Scientific Reasoning hard

A bar chart that starts its vertical scale at 40 rather than 0, compared with a chart whose scale begins at 0, is most likely to have which effect?

• A. It exaggerates the apparent difference between the groups (correct)
• B. It understates the true difference between the groups
• C. It reduces random error in the measurements
• D. It makes the conclusion more generalizable

Explanation: Starting the vertical axis at 40 rather than 0 compresses the scale so small differences between bars appear large, exaggerating the apparent gap between groups. It does not change the underlying data, so it cannot eliminate sampling error, improve precision, or make conclusions more generalizable.