English Vocabulary · Grade 9 Live Review Preview
9th Grade Vocabulary Words
Ninth grade marks the transition to high-school reading and writing across literature, argument, research, biology, physical and Earth science, algebra, computing, world history, civics, and geography. This level develops precise academic and domain-specific vocabulary while strengthening context, nuance, source evaluation, figurative language, and evidence-based communication.
This independently authored 800-word beta curriculum is arranged in twenty-three pages of up to thirty-five words. Pages containing words 1–500 include five cloze questions drawn only from that enhanced range; words 501–800 remain fully visible and editable as list pages while the expanded practice layer is developed. Each row includes a subject-field label and an editable word-study note about a transparent affix, compound structure, capitalization, or dictionary base form. The cited Grade 9 resources calibrate difficulty and study skills only; all learner-facing definitions, examples, quizzes, and descriptions are original KSSR copy.
Please note: the vocabulary lists for grades 9~11 have been selected to ensure no overlap with the previous grade level. If the words are too specialized or difficult for you, please go back to grade levels 4~8 and review the words on those pages.
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| # | Word | Details | Meaning | Sample sentence |
|---|---|---|---|---|
| 211 | prokaryote | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: prokaryote is the dictionary headword; compare its inflected or derived forms in context. | an organism whose cell lacks a nucleus and other membrane-bound organelles | A bacterium is a prokaryote with DNA located in its cell interior. |
| 212 | eukaryote | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: eukaryote is the dictionary headword; compare its inflected or derived forms in context. | an organism whose cells contain a nucleus and membrane-bound organelles | A mushroom is a eukaryote because its cells enclose DNA inside nuclei. |
| 213 | facilitated diffusion | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: facilitated + diffusion. Study the complete expression as one field-specific unit. | passive movement across a membrane through a transport protein | Glucose can enter some cells by facilitated diffusion. |
| 214 | osmosis | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: osmosis is the dictionary headword; compare its inflected or derived forms in context. | the movement of water across a selectively permeable membrane toward greater solute concentration | Through osmosis, water entered the cell from the dilute solution. |
| 215 | active transport | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: active + transport. Study the complete expression as one field-specific unit. | movement across a cell membrane that requires energy, often against a concentration difference | The sodium-potassium pump uses active transport. |
| 216 | passive transport | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: passive + transport. Study the complete expression as one field-specific unit. | movement across a cell membrane without the cell spending energy | Simple diffusion is a form of passive transport. |
| 217 | concentration gradient | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: concentration + gradient. Study the complete expression as one field-specific unit. | a difference in the amount of a substance across a distance or membrane | Oxygen moves down its concentration gradient into the cell. |
| 218 | selectively permeable | adjective StudyField: Grade 9 life-science and ecology term Word study: Term structure: selectively + permeable. Study the complete expression as one field-specific unit. | allowing some substances to cross while blocking others | The cell membrane is selectively permeable. |
| 219 | enzyme specificity | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: enzyme + specificity. Study the complete expression as one field-specific unit. | the tendency of an enzyme to act only on a particular substrate or small group of substrates | Enzyme specificity allows lactase to act on lactose rather than every sugar. |
| 220 | substrate | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: substrate is the dictionary headword; compare its inflected or derived forms in context. | the substance on which an enzyme acts | The substrate fits into the enzyme's active site. |
| 221 | activation energy | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: activation + energy. Study the complete expression as one field-specific unit. | the minimum energy needed to begin a chemical reaction | An enzyme lowers the activation energy of a cellular reaction. |
| 222 | cellular respiration | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: cellular + respiration. Study the complete expression as one field-specific unit. | the process by which cells release usable energy from food molecules | During cellular respiration, cells transfer energy from glucose into ATP. |
| 223 | light-dependent reaction | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: light + dependent + reaction. Study the complete expression as one field-specific unit. | the stage of photosynthesis that captures light energy and splits water | The light-dependent reaction occurs in the thylakoid membranes. |
| 224 | glycolysis | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: glycolysis is the dictionary headword; compare its inflected or derived forms in context. | the first stage of glucose breakdown, occurring in the cell's cytoplasm | Glycolysis splits one glucose molecule into smaller molecules. |
| 225 | fermentation | noun StudyField: Grade 9 life-science and ecology term Word study: Suffix focus: -ation commonly forms a noun naming an action, process, or result. | an energy-releasing process that allows glycolysis to continue without oxygen | Yeast uses fermentation to produce carbon dioxide in bread dough. |
| 226 | aerobic | adjective StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: aerobic is the dictionary headword; compare its inflected or derived forms in context. | requiring or occurring in the presence of oxygen | Aerobic respiration releases more usable energy than fermentation. |
| 227 | anaerobic | adjective StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: anaerobic is the dictionary headword; compare its inflected or derived forms in context. | occurring without oxygen | Some microorganisms carry out anaerobic metabolism in deep mud. |
| 228 | ATP | noun StudyField: Grade 9 life-science and ecology term Word study: Capitalization focus: ATP is an abbreviation or initialism; preserve its capital letters. | a molecule that transfers immediately usable energy within cells | Muscle contraction uses energy released when ATP loses a phosphate group. |
| 229 | metabolic regulation | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: metabolic + regulation. Study the complete expression as one field-specific unit. | control of the chemical pathways that sustain an organism | Metabolic regulation slows a pathway when enough of its product has accumulated. |
| 230 | metabolic pathway | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: metabolic + pathway. Study the complete expression as one field-specific unit. | a linked series of chemical reactions in a cell | Each step of a metabolic pathway is usually controlled by a particular enzyme. |
| 231 | amino acid | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: amino + acid. Study the complete expression as one field-specific unit. | a small organic molecule that serves as a building block of proteins | The order of each amino acid determines how a protein folds. |
| 232 | nucleotide | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: nucleotide is the dictionary headword; compare its inflected or derived forms in context. | the basic building block of DNA and RNA, containing a sugar, phosphate, and nitrogenous base | A nucleotide in DNA may contain the base adenine. |
| 233 | nucleic acid | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: nucleic + acid. Study the complete expression as one field-specific unit. | a DNA or RNA molecule that stores or helps express genetic information | DNA is a nucleic acid made of two nucleotide strands. |
| 234 | carbohydrate | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: carbohydrate is the dictionary headword; compare its inflected or derived forms in context. | an organic molecule of sugars that can provide energy or structural material | A potato stores carbohydrate mainly as starch. |
| 235 | lipid | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: lipid is the dictionary headword; compare its inflected or derived forms in context. | a water-insoluble organic molecule such as a fat, oil, wax, or steroid | A phospholipid is a lipid found in cell membranes. |
| 236 | phospholipid | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: phospholipid is the dictionary headword; compare its inflected or derived forms in context. | a lipid with a water-attracting head and water-repelling tails | Phospholipid molecules form a double layer around the cell. |
| 237 | macromolecule | noun StudyField: Grade 9 life-science and ecology term Word study: Prefix focus: macro- means large-scale. | a very large biological molecule built from smaller units | A protein is a macromolecule made from amino acids. |
| 238 | polymer | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: polymer is the dictionary headword; compare its inflected or derived forms in context. | a large molecule formed from many repeating or related smaller units | Starch is a polymer composed of glucose units. |
| 239 | monomer | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: monomer is the dictionary headword; compare its inflected or derived forms in context. | a small molecular unit that can join with others to form a polymer | A nucleotide acts as a monomer in a nucleic acid. |
| 240 | protein folding | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: protein + folding. Study the complete expression as one field-specific unit. | the process by which a protein chain takes on its functional three-dimensional shape | A temperature change can disrupt protein folding. |
| 241 | chromosome duplication | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: chromosome + duplication. Study the complete expression as one field-specific unit. | the copying of a chromosome's DNA before cell division | Chromosome duplication produces two sister chromatids. |
| 242 | chromatid | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: chromatid is the dictionary headword; compare its inflected or derived forms in context. | one of two identical DNA copies joined after a chromosome is duplicated | Each chromatid separates during mitosis. |
| 243 | centromere | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: centromere is the dictionary headword; compare its inflected or derived forms in context. | the chromosome region that joins sister chromatids and attaches to division machinery | Spindle fibers connect near the centromere. |
| 244 | homologous pair | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: homologous + pair. Study the complete expression as one field-specific unit. | two chromosomes carrying the same kinds of genes, one inherited from each parent | A homologous pair may contain different alleles of a gene. |
| 245 | gamete | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: gamete is the dictionary headword; compare its inflected or derived forms in context. | a reproductive cell containing one set of chromosomes | A human gamete has twenty-three chromosomes. |
Vocabulary reading and practice
Energy and Cell Division
Reading practice for pages 7–9. Five relevant words are highlighted.
English reading
Before a cell divides, chromosome duplication preserves genetic instructions for both new cells. ATP supplies energy for active transport, which moves substances against a concentration gradient. Passive transport requires no direct energy input. Meanwhile, correct protein folding allows many cell structures and enzymes to function as their shapes require.
Translation
Reading comprehension
1. Why does chromosome duplication occur?
It preserves genetic instructions for both new cells.
2. Which process uses ATP?
Active transport uses ATP.
3. Why is protein folding important?
A protein's shape enables its function.
Vocabulary quiz
Complete 5 review questions for this page.
1. A temperature change can disrupt ___.
Answer: protein folding
2. The sodium-potassium pump uses ___.
Answer: active transport
3. Muscle contraction uses energy released when ___ loses a phosphate group.
Answer: ATP
4. ___ produces two sister chromatids.
Answer: chromosome duplication
5. Simple diffusion is a form of ___.
Answer: passive transport
Vocabulary chart page
This page focuses on the word chart. Reading passages appear once in each three-page group, while cloze quizzes remain in the established enhanced range for this level.
Sources and curriculum references
These references guide selection and calibration. Definitions, sample sentences, readings, questions, and teaching notes are independently written and reviewed.
- GreatSchools: 9th Grade Vocabulary Words
- Victoria University of Wellington: Coxhead Academic Word List
- Common Core: Language Standards for Grades 9–10
- Common Core: Science and Technical Subjects, Grades 9–10
- WikDict downloadable bilingual dictionaries
- Kaikki.org / Wiktextract machine-readable Wiktionary data
- Language-Learning-decks public flashcard datasets
- SBBIC English-to-Khmer Dictionary
- English–Khmer Dictionary Dataset (machine-generated Khmer fallback; human review required)
- PanLex meanings snapshot (direct CC0 gap candidates; human review required)
- Cambridge bilingual dictionaries (individual editorial sense checks)
- Collins English–Hindi Dictionary (individual editorial checks)
- Hindwi and Rekhta dictionaries (individual Hindi/Urdu checks)
- National Institute of Korean Language: Basic Korean Dictionary
- JMdict/EDRDG Japanese dictionary project
- CC-CEDICT Chinese dictionary project
- VDict Vietnamese Dictionary (individual editorial check)
- Google Translate (machine-assisted lesson-reading draft; fluent review required)
- Kuperman et al.: Age-of-acquisition ratings for 30,000 English words
- The Princeton Review, Word Smart (2006 and 2012 editions; bibliographic calibration only).

