TEAS Ready📖 TEAS glossary: word parts and key terms
185 prefixes, suffixes, roots and key terms for the TEAS, each explained in one sentence with the lesson that teaches it.
Prefixes
a-, an-
Without or not, as in apnea (absence of breathing) and anuria (no urine output).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
ab-
Away from, as in abduction (moving a limb away from the body's midline).
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ad-
Toward, as in adduction (moving a limb toward the body's midline).
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anti-
Against or opposing, as in antipyretic (a medicine that works against fever).
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auto-
Self, as in autoimmune (the immune system attacking the body's own tissue).
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bi-
Two or twice, as in bilateral (on both sides).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
brady-
Slow, as in bradycardia (a slow heart rate).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
contra-
Against or opposite, as in contraindication (a reason not to give a treatment).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
de-
Remove, reverse or down, as in dehydration (loss of water from the body).
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dys-
Difficult, painful or abnormal, as in dysphagia (difficulty swallowing).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
endo-
Within or inside, as in endoscopy (looking inside a hollow organ with a scope).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
epi-
Upon or above, as in epidermis (the outer layer of the skin).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
eu-
Good or normal, as in eupnea (normal, easy breathing).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
exo-, ecto-
Outside or outer, as in exocrine gland (a gland that releases secretions through a duct to the outside or into a cavity).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
hemi-, semi-
Half, as in hemiplegia (paralysis of one side of the body).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
hyper-
Above normal or excessive, as in hyperglycemia (high blood sugar).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
hypo-
Below normal, under or deficient, as in hypothermia (body temperature below normal).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
infra-
Below or beneath, as in infraorbital (below the eye socket).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
inter-
Between, as in intercostal (between the ribs).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
intra-
Within or inside, as in intravenous (within a vein).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
macro-
Large, as in macrophage (a large white blood cell that engulfs debris and germs).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
micro-
Small, as in microorganism (a living thing too small to see without a microscope).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
mis-
Wrongly or badly, as in misdiagnose (to identify a condition incorrectly).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
mono-, uni-
One or single, as in unilateral (on one side only).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
neo-
New, as in neonate (a newborn baby).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
olig-
Few or scanty, as in oliguria (very low urine output).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
peri-
Around, as in pericardium (the sac around the heart).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
poly-
Many or much, as in polyuria (producing too much urine).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
post-
After or behind, as in postoperative (after surgery).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
pre-
Before, as in prenatal (before birth).
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re-
Again or back, as in reinfection (being infected again).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
sub-
Under or below, as in subcutaneous (beneath the skin).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
supra-
Above, as in suprapubic (above the pubic bone).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
tachy-
Fast, as in tachycardia (a fast heart rate).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
trans-
Across or through, as in transdermal (through the skin, as with a medicine patch).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
tri-
Three, as in triceps (the arm muscle with three heads).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
un-, in-
Not, as in unconscious (not awake or aware) and inactive (not active).
📚 Learn it: Prefixes: hyper-, hypo-, brady-, tachy- and more
Suffixes
-able, -ible
Capable of being, used to form adjectives such as treatable (able to be treated).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-algia
Pain, as in myalgia (muscle pain).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-cyte
Cell, as in leukocyte (a white blood cell).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ectomy
Surgical removal, as in appendectomy (removal of the appendix).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-emia
A condition of the blood, as in anemia (too few red blood cells or too little hemoglobin).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ful
Full of, used to form adjectives such as painful (full of pain).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-gram
A record or image, as in electrocardiogram (a record of the heart's electrical activity).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-graphy
The process of recording or imaging, as in mammography (imaging of the breast).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-itis
Inflammation, as in arthritis (inflammation of a joint).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ize
To make or become, used to form verbs such as sterilize (to make free of germs).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-less
Without, used to form adjectives such as painless (without pain).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-megaly
Enlargement, as in hepatomegaly (an enlarged liver).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ment
The act, state or result of, used to form nouns such as treatment (the act of treating).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ology, -ologist
The study of (-ologist: one who studies), as in cardiology (the study of the heart).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-oma
Tumor or mass, as in lipoma (a fatty, usually harmless lump).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-osis
An abnormal condition, as in cyanosis (an abnormal bluish color of the skin).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ostomy
Creating a surgical opening, as in colostomy (an opening from the colon to the outside of the abdomen).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-otomy
Cutting into, as in tracheotomy (an incision into the windpipe).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-pathy
Disease, as in neuropathy (disease of the nerves).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-penia
Deficiency or lack, as in leukopenia (too few white blood cells).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-plasty
Surgical repair or reshaping, as in rhinoplasty (surgical repair of the nose).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-rrhea
Flow or discharge, as in diarrhea (frequent, watery flow of stool).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-scope
An instrument for viewing, as in otoscope (a tool for looking inside the ear).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-scopy
A visual examination with a scope, as in arthroscopy (looking inside a joint).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-tion, -sion
The act or process of, used to form nouns such as observation (the act of observing).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
-ous, -al, -ic
Pertaining to, used to form adjectives such as venous (relating to veins) and cardiac (relating to the heart).
📚 Learn it: Suffixes: -itis, -ectomy, -ology, -algia and more
Roots
angi, vas
Vessel, as in angioplasty (repair of a blood vessel) and vascular (relating to vessels).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
arthr
Joint, as in arthritis (inflammation of a joint).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
bio
Life, as in biopsy (taking tissue from a living body to examine).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
cardi
Heart, as in cardiology (the study of the heart).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
cephal
Head, as in cephalgia (headache).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
chron
Time, as in chronic (lasting a long time).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
cost
Rib, as in intercostal (between the ribs).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
cutane
Skin (Latin), as in subcutaneous (beneath the skin).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
cyt
Cell, as in cytoplasm (the gel-like material inside a cell).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
derm, dermat
Skin (Greek), as in dermatitis (inflammation of the skin).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
dict
Say or speak, as in contradict (to say the opposite).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
encephal
Brain, as in encephalitis (inflammation of the brain).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
enter
Intestine, as in gastroenteritis (inflammation of the stomach and intestines).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
erythr
Red, as in erythrocyte (a red blood cell).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
gastr
Stomach, as in gastritis (inflammation of the stomach).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
glyc, gluc
Sugar, as in hypoglycemia (low blood sugar).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
graph
Write or record, as in biography (a written account of a life).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
hem, hemat
Blood, as in hematology (the study of blood).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
hepat
Liver, as in hepatitis (inflammation of the liver).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
leuk
White, as in leukocyte (a white blood cell).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
my, myo
Muscle, as in myocardium (the muscle layer of the heart).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
nephr
Kidney (Greek), as in nephritis (inflammation of the kidney).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
neur
Nerve, as in neuralgia (nerve pain).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
ophthalm
Eye, as in ophthalmologist (a doctor who treats eye diseases).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
oste
Bone, as in osteoporosis (a condition of porous, weakened bone).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
ot
Ear, as in otitis (inflammation of the ear).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
path
Disease, as in pathogen (a germ that causes disease).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
phag
Eat or swallow, as in dysphagia (difficulty swallowing).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
pneum
Lung or air, as in pneumonia (an infection that inflames the lungs).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
port
Carry, as in transport (to carry across).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
pulmon
Lung, as in pulmonary (relating to the lungs).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
ren
Kidney (Latin), as in renal failure (loss of kidney function).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
rhin
Nose, as in rhinitis (inflammation of the lining of the nose).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
spect
Look or see, as in inspect (to look at closely).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
therm
Heat, as in hyperthermia (body temperature above normal).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
ven, phleb
Vein, as in intravenous (within a vein) and phlebotomy (drawing blood from a vein).
📚 Learn it: Roots: cardi, gastr, derm, neur and other medical roots
Reading
Main idea
The one point that the whole passage supports; for example, "Teens need more sleep than most get" (not just "sleep").
📚 Learn it: Main idea and summary: what is the whole text about?
Topic
The subject of a text in a word or phrase, without the author's point about it; for example, "hand washing."
📚 Learn it: Main idea and summary: what is the whole text about?
Summary
A short restatement of the main idea and key points in your own words, with no new facts or opinions; for example, two sentences that cover a five-paragraph article.
📚 Learn it: Main idea and summary: what is the whole text about?
Supporting detail
A fact, example or reason that backs up the main idea; for example, a statistic about fewer sick days after hand washing.
📚 Learn it: Supporting details: find the fact the question asks for
Inference
A logical conclusion drawn from clues in the text that the author does not state directly; for example, wet umbrellas by the door suggest it is raining.
📚 Learn it: Inferences and conclusions: reading between the lines
Sequence
The order in which events or steps happen, often signaled by words such as first, next, then and finally.
Fact
A statement that can be checked and proven true or false; for example, "The clinic opens at 8 a.m."
Opinion
A statement of belief, feeling or judgment that cannot be proven; for example, "The clinic has the friendliest staff in town."
Bias
A one-sided slant that favors one view and leaves out or downplays others; for example, a review written by the product's own seller.
Context clue
A hint in nearby words that shows what an unfamiliar word means; for example, "unlike" signals a contrast (antonym) clue.
Author's purpose
The reason an author writes: usually to inform, persuade, entertain or explain; for example, a flu-shot flyer urging people to get vaccinated aims to persuade.
📚 Learn it: Author's purpose: why did the writer write this?
Point of view
The perspective a text is told from or the author's position on a subject; for example, "I" and "we" signal first person.
📚 Learn it: Point of view and tone: who is talking and how do they feel?
Tone
The author's attitude toward the subject, shown through word choice; for example, a tone can be hopeful, critical or neutral.
📚 Learn it: Point of view and tone: who is talking and how do they feel?
Text structure
The way a text is organized, such as cause and effect, compare and contrast, problem and solution, or sequence; for example, "as a result" signals cause and effect.
📚 Learn it: Text structure and text features: how the text is built
Text feature
A part of a text that helps readers find or understand information, such as headings, captions, bold words and indexes; for example, a heading that labels a section "Side Effects."
📚 Learn it: Text structure and text features: how the text is built
Claim
The position an author argues for and tries to prove with evidence; for example, "Schools should start later in the morning."
📚 Learn it: Evaluating an argument: claim, evidence and reasoning
Theme
The central message or lesson a text conveys; for example, two stories may share the theme that persistence pays off.
📚 Learn it: Comparing two texts: where they agree and where they differ
Primary source
A firsthand, original record created at the time by someone involved; for example, a nurse's diary written during a hospital strike.
📚 Learn it: Primary vs secondary sources and judging credibility
Secondary source
A work that describes, analyzes or summarizes primary sources; for example, a textbook chapter about the history of nursing.
📚 Learn it: Primary vs secondary sources and judging credibility
Credibility
How trustworthy a source is, based on the author's expertise, evidence, date and purpose; for example, a current report from a medical research center is more credible than an anonymous post.
📚 Learn it: Primary vs secondary sources and judging credibility
Writing
Prewriting
The planning stage before drafting: brainstorming, researching and organizing ideas; for example, listing every idea you have about sleep before writing sentences.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Outline
A plan that arranges the thesis, main points and supporting details in order, often with Roman numerals for main points and letters for details.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Thesis statement
One sentence that states the main claim of an essay, usually in the introduction; for example, "Hospitals should adopt quiet hours because rest speeds healing."
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Drafting
Turning the plan into full sentences and paragraphs without aiming for perfection; for example, writing the whole first version of a report in one sitting.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Revising
Improving the content and organization of a draft by adding, cutting or moving ideas; for example, deleting an off-topic story and adding evidence.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Editing
Correcting sentence-level errors in grammar, punctuation, spelling and word choice; for example, fixing a subject-verb agreement error.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Proofreading
The final careful read to catch typos and small errors before publishing; for example, catching a typo such as "becuase" before turning in the final copy.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Citation
A note that credits the source of a quote, paraphrase or fact; for example, naming the author and article a statistic came from.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Plagiarism
Presenting someone else's words or ideas as your own without credit; for example, pasting a website sentence into an essay with no citation.
📚 Learn it: The writing process: prewriting, drafting, revising, editing
Denotation
A word's literal, dictionary meaning; for example, both "slender" and "skinny" denote "thin."
📚 Learn it: Word choice: denotation, connotation and precise words
Connotation
The positive, negative or neutral feeling a word carries beyond its literal meaning; for example, "frugal" sounds approving, "stingy" sounds critical.
📚 Learn it: Word choice: denotation, connotation and precise words
Homophone
Words that sound the same but differ in meaning and spelling; for example, their, there and they're.
📚 Learn it: Word choice: denotation, connotation and precise words
Sentence fragment
A group of words punctuated as a sentence that lacks a subject, a verb or a complete thought; for example, "Because the shift ran late."
📚 Learn it: Sentence fragments, run-ons and comma splices: how to fix them
Run-on sentence
Two or more independent clauses joined without correct punctuation or a conjunction; for example, "The bus was late I missed class."
📚 Learn it: Sentence fragments, run-ons and comma splices: how to fix them
Complex sentence
A sentence with one independent clause and at least one dependent clause; for example, "When the alarm rang, the nurse checked the monitor."
📚 Learn it: Sentence types: simple, compound, complex and compound-complex
Antecedent
The noun that a pronoun refers to; for example, in "Maria lost her badge," Maria is the antecedent of her.
Parallel structure
Using the same grammatical form for items in a list or pair; for example, "reading, writing and studying" (not "reading, writing and to study").
📚 Learn it: Misplaced and dangling modifiers, and parallel lists
Transition
A word or phrase that shows how ideas connect, such as however (contrast), therefore (result) and for example (illustration).
📚 Learn it: Topic sentences, transitions and paragraph order
Topic sentence
The sentence that states the main idea of a paragraph, often placed first; for example, "Regular walking improves mood in several ways."
📚 Learn it: Topic sentences, transitions and paragraph order
Math
Numerator and denominator
The numerator is the top number of a fraction (parts taken) and the denominator is the bottom number (equal parts in the whole); for example, in 3/4, 3 is the numerator and 4 is the denominator.
Percent
A part per hundred; for example, 25% = 25/100 = 0.25.
Order of operations
The rule for evaluating expressions: parentheses, exponents, multiplication and division left to right, then addition and subtraction left to right; for example, 2 + 3 × 4 = 14.
📚 Learn it: Order of operations, negative numbers and absolute value
Variable
A letter that stands for an unknown or changing number; for example, in 2x + 5 = 11, x = 3.
Ratio
A comparison of two quantities by division; for example, 3 nurses to 12 patients is a ratio of 1:4.
Proportion
An equation stating that two ratios are equal, often solved by cross-multiplying; for example, 2/5 = x/20, so x = 8.
Rate
A ratio comparing quantities with different units; for example, 120 mL per hour.
Inequality
A statement that one quantity is greater or less than another, using <, >, ≤ or ≥; for example, x + 2 > 5 means x > 3.
📚 Learn it: Expressions, inequalities, word problems, estimation and rounding
Mean
The sum of the values divided by how many values there are; for example, the mean of 4, 6 and 8 is 18 ÷ 3 = 6.
Median
The middle value when data are in order (the mean of the two middle values if the count is even); for example, the median of 2, 5, 9 is 5.
Mode
The value that appears most often in a data set; for example, the mode of 3, 4, 4, 7 is 4.
Range
The highest value minus the lowest value; for example, the range of 10, 15 and 22 is 12.
Outlier
A value far from the rest of the data that can pull the mean toward it; for example, 95 in the set 10, 12, 11, 95.
Correlation
How two variables change together: positive (both rise), negative (one rises as the other falls) or none; for example, hours studied and test scores often show a positive correlation.
Perimeter
The total distance around a flat shape; for example, a 3 ft by 5 ft rectangle has a perimeter of 16 ft.
Area
The amount of surface a flat shape covers, in square units; for example, a 3 ft by 5 ft rectangle has an area of 15 sq ft.
Circumference
The distance around a circle: C = πd = 2πr; for example, a circle with a 10 cm diameter has a circumference of about 31.4 cm.
Volume
The amount of space a solid takes up, in cubic units; for example, a 2 × 3 × 4 cm box has a volume of 24 cm³.
Conversion factor
A ratio equal to 1 that changes units without changing the amount; for example, 1 kg / 2.2 lb converts 44 lb to 20 kg.
Metric prefixes
Prefixes that scale metric units by powers of 10: kilo- = 1,000, centi- = 1/100, milli- = 1/1,000; for example, 1 L = 1,000 mL.
Science
Sagittal plane
A vertical plane that divides the body into left and right parts (the midsagittal plane makes equal halves); for example, a cut down the midline between the eyes.
📚 Learn it: Body orientation: anatomical position, planes, directions, cavities and regions
Frontal (coronal) plane
A vertical plane that divides the body into front (anterior) and back (posterior) parts; for example, a cut from ear to ear down through the shoulders.
📚 Learn it: Body orientation: anatomical position, planes, directions, cavities and regions
Transverse plane
A horizontal plane that divides the body into upper (superior) and lower (inferior) parts; for example, a cross-section at the waist.
📚 Learn it: Body orientation: anatomical position, planes, directions, cavities and regions
Proximal and distal
Proximal means closer to where a limb attaches to the trunk, and distal means farther away; for example, the elbow is proximal to the wrist.
📚 Learn it: Body orientation: anatomical position, planes, directions, cavities and regions
Medial and lateral
Medial means toward the body's midline, and lateral means away from it; for example, the nose is medial to the eyes.
📚 Learn it: Body orientation: anatomical position, planes, directions, cavities and regions
Homeostasis
The body's process of keeping internal conditions such as temperature and blood sugar stable; for example, sweating to cool down on a hot day.
📚 Learn it: Endocrine system: glands, hormones and feedback loops
Hypothesis
A testable prediction about how variables are related; for example, "If plants get more light, then they will grow taller."
📚 Learn it: Variables, controls and hypotheses: designing a fair test
Independent variable
The factor the researcher changes on purpose to test its effect; for example, the amount of light given to each plant.
📚 Learn it: Variables, controls and hypotheses: designing a fair test
Dependent variable
The factor that is measured to see whether it responds to the change; for example, the height each plant grows.
📚 Learn it: Variables, controls and hypotheses: designing a fair test
Control group
The group that does not receive the tested treatment, used for comparison; for example, plants kept under normal light.
📚 Learn it: Variables, controls and hypotheses: designing a fair test
Correlation vs causation
Two things rising or falling together (correlation) does not prove that one causes the other (causation); for example, ice cream sales and sunburns both rise in summer, but neither causes the other.
📚 Learn it: Logic and evidence: correlation vs causation, observation vs inference
Organelle
A specialized structure inside a cell that performs a specific job; for example, mitochondria release energy from food molecules.
Osmosis
The movement of water across a selectively permeable membrane toward the side with more dissolved solute; for example, a red blood cell swells in pure water.
Diffusion
The movement of particles from an area of higher concentration to lower concentration without using energy; for example, oxygen moving from the lungs' air sacs into the blood.
Mitosis
Cell division that produces two genetically identical body cells; for example, skin cells dividing to heal a cut.
Meiosis
Cell division that produces four sex cells, each with half the usual number of chromosomes; for example, the formation of egg and sperm cells.
Transcription
The process of copying a gene's DNA into messenger RNA, which takes place in the nucleus; for example, the first step of protein synthesis.
Translation
The process in which a ribosome reads messenger RNA and links amino acids into a protein; for example, the second step of protein synthesis.
Genotype and phenotype
The genotype is an organism's allele combination, and the phenotype is the trait that shows; for example, genotype Bb, phenotype brown eyes.
Dominant allele
An allele whose trait shows even when only one copy is present (a recessive allele shows only with two copies); for example, B in Bb.
Enzyme
A protein that speeds up a chemical reaction in the body without being used up; for example, amylase breaks down starch.
📚 Learn it: Macromolecules: carbohydrates, lipids, proteins and nucleic acids
Isotope
Atoms of the same element with the same number of protons but different numbers of neutrons; for example, carbon-12 and carbon-14.
Physical change
A change in form or state that does not create a new substance; for example, ice melting into water.
📚 Learn it: States of matter and physical vs chemical change
Covalent bond
A bond in which atoms share electrons (an ionic bond transfers them); for example, the bonds in a water molecule.
Catalyst
A substance that speeds up a reaction without being used up; for example, enzymes are biological catalysts.
Solute and solvent
The solute is the substance dissolved, and the solvent is what it dissolves in; for example, in salt water, salt is the solute and water is the solvent.
pH
A 0 to 14 scale of acidity: below 7 is acidic, 7 is neutral, above 7 is basic; for example, normal blood pH is about 7.4, slightly basic.