TEAS 7 Science Exam Flashcards

Q: How many questions are on the TEAS 7 Science section and how long is it?

The Science section has 50 questions and a 60-minute time limit. Of those, 44 are scored and 6 are unscored pretest items that ATI distributes proportionally across the exam. Science is the largest single content area on the TEAS 7, worth 29% of the scored test. The full TEAS 7 is 170 questions in 209 minutes across Reading (45 questions, 55 minutes), Math (38 questions, 57 minutes), Science (50 questions, 60 minutes), and English and Language Usage (37 questions, 37 minutes).

Q: What topics are on the TEAS 7 Science section?

ATI's published content outline lists four sub-content areas by scored question count: Human Anatomy and Physiology (18 scored questions, 12% of the whole test), Biology (9 questions, 6%), Chemistry (8 questions, 5%), and Scientific Reasoning (9 questions, 6%). Anatomy and physiology is by far the heaviest, at roughly 41% of the Science score, and covers general anatomical orientation plus 11 body systems.

Q: What score do I need to pass TEAS Science?

There is no national passing score. ATI does not set a pass/fail standard for the TEAS; each nursing or allied health program sets its own minimum, and ATI describes a competitive score as roughly 70-75%. Many programs also look at your Science sub-score separately from your total score, so check the specific requirements of every program you are applying to.

Q: Can I use a calculator on the TEAS Science section?

Plan on working without one. ATI does not allow you to bring your own calculator; it provides a four-function calculator, built into the exam online or supplied by the proctor on paper, and it is used for the Mathematics section. Science questions are written to be answered without calculation, so practice metric conversions and simple ratio work by hand.

Q: How soon can I retake the TEAS?

If you take a TEAS at ATI exam, ATI requires a 14-day wait between attempts. If you test through an institution, the waiting period is set by that school, and many require 30 days. ATI does not cap the number of attempts, but most programs limit how many scores they will consider, so confirm your program's rule before rebooking.

Q: Are there breaks during the TEAS exam?

ATI does not schedule breaks during the 209-minute exam. You may take a brief unscheduled break once you finish the Math section, which is immediately before Science. Each section is timed separately, unused time does not carry over, and once a section closes you cannot return to it.

Q: Why is Science considered the hardest TEAS section?

It carries the widest content range of any section: anatomy and physiology alone spans 11 body systems, and you also need cell biology, genetics, general chemistry, and experimental design. At 60 minutes for 50 questions you get about 72 seconds per item, so recall has to be automatic. Flashcards are effective here because most Science items reward direct factual recall rather than long calculation.

Question 1

Proximal vs. distal

Accepted Answer

Proximal means closer to the trunk or point of attachment; distal means farther from it. The knee is proximal to the ankle. These two describe limbs, while superior and inferior describe up-and-down position on the body as a whole.

Question 2

The three anatomical planes

Accepted Answer

Sagittal divides the body into left and right; frontal (coronal) divides anterior (front) from posterior (back); transverse divides superior (top) from inferior (bottom). A midsagittal cut produces two equal halves.

Question 3

Where does gas exchange actually happen in the lungs?

Accepted Answer

In the alveoli, thin-walled air sacs wrapped in capillaries where oxygen diffuses into blood and carbon dioxide diffuses out. The trachea, bronchi, and bronchioles only conduct air; no exchange occurs there.

Question 4

What happens mechanically during inhalation?

Accepted Answer

The diaphragm contracts and flattens while external intercostals lift the ribs, expanding the thoracic cavity. That drops pressure inside the lungs below atmospheric pressure, so air flows in. Quiet exhalation is passive elastic recoil, requiring no muscle contraction.

Question 5

Trace the path of blood through the heart

Accepted Answer

Body -> vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmonary valve -> lungs -> pulmonary veins -> left atrium -> mitral (bicuspid) valve -> left ventricle -> aortic valve -> aorta -> body.

Question 6

Arteries vs. veins

Accepted Answer

Arteries carry blood away from the heart under high pressure and have thick muscular walls. Veins return blood to the heart at low pressure and contain one-way valves. Direction defines them, not oxygen content: the pulmonary artery carries deoxygenated blood.

Question 7

Pulmonary vs. systemic circuit

Accepted Answer

The pulmonary circuit runs right ventricle -> lungs -> left atrium to pick up oxygen. The systemic circuit runs left ventricle -> body -> right atrium to deliver it. The left ventricle has the thickest wall because it pumps against whole-body resistance.

Question 8

Where are most nutrients absorbed?

Accepted Answer

In the small intestine, mainly the jejunum, where villi and microvilli create an enormous surface area. The large intestine absorbs water and electrolytes and forms feces, but absorbs very few nutrients.

Question 9

Where does chemical digestion of carbohydrates vs. protein begin?

Accepted Answer

Carbohydrate digestion starts in the mouth with salivary amylase. Protein digestion starts in the stomach, where hydrochloric acid converts pepsinogen into active pepsin. Most fat digestion happens later in the small intestine using bile and lipase.

Question 10

Central vs. peripheral nervous system

Accepted Answer

The CNS is the brain and spinal cord, handling integration and command. The PNS is every nerve outside them, split into somatic (voluntary skeletal muscle) and autonomic (involuntary organs). The autonomic branch further divides into sympathetic and parasympathetic.

Question 11

Sympathetic vs. parasympathetic effects

Accepted Answer

Sympathetic is fight or flight: raises heart rate, dilates pupils and bronchioles, slows digestion. Parasympathetic is rest and digest: lowers heart rate, constricts pupils, stimulates digestion. They act in opposition on the same organs to keep balance.

Question 12

The three muscle tissue types

Accepted Answer

Skeletal: striated, multinucleated, voluntary, moves bones. Cardiac: striated, branched, involuntary, joined by intercalated discs, found only in the heart. Smooth: non-striated, involuntary, lines hollow organs and blood vessels.

Question 13

Origin vs. insertion of a muscle

Accepted Answer

The origin attaches to the stationary bone; the insertion attaches to the bone that moves. Muscles can only pull, never push, so they work in antagonistic pairs: the biceps flexes the elbow while the triceps extends it.

Question 14

Where is sperm produced and where does it mature?

Accepted Answer

Sperm are produced in the seminiferous tubules of the testes and mature and are stored in the epididymis. The vas deferens transports them, and the seminal vesicles and prostate add fluid to form semen.

Question 15

What triggers ovulation?

Accepted Answer

A surge of luteinizing hormone (LH) near day 14 releases the oocyte from its follicle. The ruptured follicle becomes the corpus luteum, which secretes progesterone to maintain the uterine lining. Fertilization normally occurs in the fallopian tube, not the uterus.

Question 16

The three layers of skin

Accepted Answer

Epidermis (outer, avascular, keratinized), dermis (blood vessels, nerves, hair follicles, glands), and hypodermis or subcutaneous layer (fat and insulation). Because the epidermis has no blood supply, it receives nutrients by diffusion from the dermis.

Question 17

Endocrine vs. exocrine glands

Accepted Answer

Endocrine glands are ductless and release hormones straight into the bloodstream to reach distant target cells. Exocrine glands (sweat, salivary) use ducts to deliver products onto a surface or into a cavity. Hormonal effects are slower to start but last longer than nerve signals.

Question 18

How do insulin and glucagon control blood glucose?

Accepted Answer

Insulin, from pancreatic beta cells, lowers blood glucose by driving it into cells. Glucagon, from alpha cells, raises it by breaking down liver glycogen. Together they form a negative feedback loop, the classic TEAS example of homeostasis.

Question 19

What is the functional unit of the kidney?

Accepted Answer

The nephron. It filters blood at the glomerulus, then reabsorbs water and needed solutes and secretes wastes along the tubule. Kidneys also regulate blood pressure, blood pH, and electrolyte balance, not just urine output.

Question 20

Innate vs. adaptive immunity

Accepted Answer

Innate immunity is nonspecific and immediate: skin, mucous membranes, inflammation, phagocytes, fever. Adaptive immunity is specific and slower, using B cells (antibodies) and T cells, and it forms memory, which is why a second exposure produces a faster, stronger response.

Question 21

Axial vs. appendicular skeleton

Accepted Answer

The axial skeleton (80 bones) is the skull, vertebral column, and rib cage, protecting central organs. The appendicular skeleton (126 bones) is the limbs plus the pectoral and pelvic girdles, enabling movement. The adult skeleton has 206 bones total.

Question 22

Prokaryotic vs. eukaryotic cells

Accepted Answer

Prokaryotes (bacteria) have no nucleus and no membrane-bound organelles; their DNA sits free in the cytoplasm. Eukaryotes (animals, plants, fungi, protists) have a true nucleus and organelles. Both still have ribosomes, a plasma membrane, cytoplasm, and DNA.

Question 23

Mitochondria vs. ribosomes vs. Golgi apparatus

Accepted Answer

Mitochondria generate ATP through cellular respiration. Ribosomes build proteins by reading mRNA. The Golgi apparatus modifies, packages, and ships proteins arriving from the endoplasmic reticulum. Lysosomes digest cellular waste with hydrolytic enzymes.

Question 24

Transcription vs. translation

Accepted Answer

Transcription copies DNA into messenger RNA inside the nucleus. Translation happens at the ribosome, where tRNA delivers amino acids in the order the mRNA specifies. The overall flow is DNA -> RNA -> protein.

Question 25

How do DNA and RNA differ?

Accepted Answer

DNA is double-stranded, contains deoxyribose, and pairs adenine with thymine and cytosine with guanine. RNA is single-stranded, contains ribose, and swaps uracil for thymine, so adenine pairs with uracil. Three mRNA bases form one codon, coding one amino acid.

Question 26

Genotype vs. phenotype

Accepted Answer

Genotype is the pair of alleles carried (BB, Bb, or bb); phenotype is the observable trait. BB and Bb produce the same dominant phenotype, which is why a recessive trait can skip a generation and reappear in the children of two carriers.

Question 27

What ratio results from crossing two heterozygotes (Bb x Bb)?

Accepted Answer

Genotypes come out 1 BB : 2 Bb : 1 bb, giving a 3:1 phenotypic ratio. So 75% show the dominant trait and 25% show the recessive one, meaning each child of two carriers has a 25% chance of the recessive condition.

Question 28

The four biological macromolecules and their building blocks

Accepted Answer

Carbohydrates are built from monosaccharides, proteins from amino acids, nucleic acids from nucleotides, and lipids from glycerol plus fatty acids (lipids are not true polymers). Proteins use 20 amino acids joined by peptide bonds.

Question 29

What does an enzyme do to a reaction?

Accepted Answer

It lowers activation energy so the reaction proceeds faster, and it is not consumed. Enzymes are proteins with substrate-specific active sites, and extreme heat or the wrong pH denatures them, destroying the shape and therefore the function.

Question 30

Why do antibiotics work on bacteria but not viruses?

Accepted Answer

Antibiotics attack bacterial structures such as the cell wall and bacterial ribosomes. Viruses are not cells, lack those structures, and must hijack a host cell to replicate, so they need antivirals or vaccines instead. Fungi and parasites are two further pathogen classes that antibiotics also do not treat.

Question 31

Passive vs. active transport, and what tonicity does to a cell

Accepted Answer

Diffusion and osmosis move substances down a concentration gradient and cost no ATP; active transport such as the sodium-potassium pump spends ATP to move them against it. Water follows solute, so a cell in a hypertonic solution shrinks, in a hypotonic solution swells and may burst, and in an isotonic solution shows no net change.

Question 32

Protons, neutrons, and electrons: charge, location, mass

Accepted Answer

Protons carry +1 and neutrons carry 0; both sit in the nucleus and hold nearly all the mass. Electrons carry -1, orbit in shells, and have negligible mass. The number of protons is the atomic number and defines which element it is.

Question 33

Isotope vs. ion

Accepted Answer

An isotope has a different number of neutrons, so mass changes but charge and element identity do not. An ion has a different number of electrons, so it carries a charge: losing electrons makes a positive cation, gaining them makes a negative anion.

Question 34

States of matter, phase changes, and physical vs. chemical change

Accepted Answer

Solids hold their shape and volume, liquids keep volume but take the container's shape, and gases fill it. Phase changes are physical: melting, vaporizing, and subliming absorb energy while freezing, condensing, and depositing release it, and temperature holds steady during the change. A chemical change instead makes a new substance, signaled by bubbling, a precipitate, or released heat or light.

Question 35

Ionic vs. covalent bonds

Accepted Answer

An ionic bond transfers electrons, usually from a metal to a nonmetal, and the resulting oppositely charged ions attract; these compounds have high melting points and conduct electricity when dissolved. A covalent bond shares electrons between nonmetals. Hydrogen bonds are weak attractions between molecules, and they give water its high boiling point and surface tension.

Question 36

The reaction types, and why equations must be balanced

Accepted Answer

Synthesis: A + B -> AB. Decomposition: AB -> A + B. Single replacement: A + BC -> AC + B. Double replacement: AB + CD -> AD + CB. Combustion burns a hydrocarbon in oxygen to yield carbon dioxide and water. Conservation of mass requires equal atom counts on both sides, so balance with coefficients only; changing a subscript would change the substance itself.

Question 37

What speeds up a chemical reaction?

Accepted Answer

Higher temperature, higher concentration, greater surface area, and a catalyst all increase effective molecular collisions. A catalyst lowers activation energy and is not consumed, so it changes the rate but not the products or the position of equilibrium.

Question 38

Solute vs. solvent, and what dissolves what

Accepted Answer

The solute is the substance being dissolved; the solvent does the dissolving and is present in the greater amount. Like dissolves like, so polar solvents such as water dissolve polar and ionic solutes, while nonpolar solvents dissolve fats and oils.

Question 39

What does the pH scale measure?

Accepted Answer

Hydrogen ion concentration, on a 0 to 14 scale. Below 7 is acidic, exactly 7 is neutral, above 7 is basic. It is logarithmic, so pH 4 holds ten times more H+ than pH 5 and one hundred times more than pH 6.

Question 40

How do acids and bases behave?

Accepted Answer

Acids donate H+ ions, taste sour, and turn litmus red. Bases accept H+ or release OH-, feel slippery, and turn litmus blue. An acid plus a base neutralizes into a salt and water. Normal human blood is slightly basic at pH 7.35 to 7.45.

Question 41

Metric units for length, mass, volume, and temperature

Accepted Answer

Meter for length, gram or kilogram for mass, liter for volume, and degrees Celsius for temperature (the kelvin is the SI temperature unit). Mass is the amount of matter and stays constant anywhere; weight is gravitational force and changes with location.

Question 42

Metric prefixes from kilo- to milli-

Accepted Answer

Kilo- is 1,000, hecto- 100, deka- 10, then the base unit, deci- 0.1, centi- 0.01, milli- 0.001. Each step is a factor of ten, so 1 gram equals 1,000 milligrams and 1 liter equals 1,000 milliliters.

Question 43

Which lab tool measures which quantity?

Accepted Answer

A graduated cylinder measures liquid volume, read at the bottom of the meniscus at eye level. A balance measures mass. A thermometer measures temperature. Beakers and flasks are for holding and mixing, not for precise measurement.

Question 44

Hypothesis vs. theory vs. law

Accepted Answer

A hypothesis is a testable, falsifiable prediction. A theory is a well-supported explanation backed by large amounts of evidence. A law describes what reliably happens, often as an equation, but does not explain why. A theory never gets promoted into a law.

Question 45

Reliability vs. validity

Accepted Answer

Reliability is consistency: repeated trials give the same result. Validity is accuracy: the study truly measures what it claims to. A result can be reliably wrong, so adding trials improves reliability but never fixes a flawed design.

Question 46

Why does correlation not prove causation?

Accepted Answer

Two variables can move together because of a hidden third variable or pure coincidence. Only a controlled experiment that manipulates the independent variable while holding everything else constant can support a claim that one thing causes another.

Question 47

Direct vs. inverse relationship

Accepted Answer

In a direct relationship both variables move the same way, such as more fertilizer producing more growth, and the graph slopes upward. In an inverse relationship one rises as the other falls, such as pressure and gas volume, and the graph slopes downward.

Question 48

Independent vs. dependent variable

Accepted Answer

The independent variable is what the researcher deliberately changes; the dependent variable is the outcome measured in response. On a graph the independent variable goes on the x-axis and the dependent variable on the y-axis.

Question 49

Control group vs. controlled variables

Accepted Answer

The control group gets no treatment, or a placebo, and provides the comparison baseline. Controlled variables are the factors deliberately held constant for every group. Without both, a difference in results cannot be credited to the independent variable.

Question 50

The order of the scientific method

Accepted Answer

Observe and ask a question, research, form a testable hypothesis, run a controlled experiment, collect and analyze the data, then draw a conclusion and communicate it. A result that disproves the hypothesis is still valid and useful, not a failed experiment.

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