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9th-grade-vocabulary-words

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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800 words
Words 246–280 of 800
#WordDetailsMeaningSample sentence
246zygotenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Base-form focus: zygote is the dictionary headword; compare its inflected or derived forms in context.

zigotoThe zygote begins dividing soon after fertilization.
247fertilizationnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Suffix focus: -ization forms a noun for a process of making or becoming.

1. fecundação 2. fertilizaçãoFertilization combines genetic material from two parents.
248hereditary patternnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: hereditary + pattern. Study the complete expression as one field-specific unit.

padrão hereditárioThe pedigree revealed a hereditary pattern linked to a recessive allele.
249Punnett squarenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: Punnett + square. Study the complete expression as one field-specific unit.

Praça PunnettThe Punnett square shows a one-in-four chance of the recessive genotype.
250Mendelian inheritancenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: Mendelian + inheritance. Study the complete expression as one field-specific unit.

Herança MendelianaA single-gene dominant trait may follow Mendelian inheritance.
251incomplete dominancenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: incomplete + dominance. Study the complete expression as one field-specific unit.

dominância incompletaRed and white flowers produce pink offspring through incomplete dominance.
252codominancenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Suffix focus: -ance commonly forms a noun naming an action, quality, or state.

codominânciaHuman AB blood type demonstrates codominance.
253polygenic traitnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: polygenic + trait. Study the complete expression as one field-specific unit.

traço poligênicoHuman height is a polygenic trait also affected by environment.
254sex chromosomenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: sex + chromosome. Study the complete expression as one field-specific unit.

cromossomo sexualThe X chromosome is a human sex chromosome.
255autosomenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Base-form focus: autosome is the dictionary headword; compare its inflected or derived forms in context.

autossomaHumans normally have twenty-two pairs of each autosome type.
256genetic variationnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: genetic + variation. Study the complete expression as one field-specific unit.

variação genéticaGenetic variation gives natural selection material on which to act.
257genetic disordernoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: genetic + disorder. Study the complete expression as one field-specific unit.

distúrbio genéticoA genetic disorder may result from one altered gene or an extra chromosome.
258genetic carriernoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: genetic + carrier. Study the complete expression as one field-specific unit.

portador genéticoA genetic carrier can pass the recessive allele to a child.
259gene expressionnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: gene + expression. Study the complete expression as one field-specific unit.

expressão génicaEnvironmental signals can change gene expression without altering the DNA sequence.
260gene regulationnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: gene + regulation. Study the complete expression as one field-specific unit.

regulação genéticaGene regulation allows liver cells and nerve cells to use different sets of genes.
261biotechnologynoun
Study

Field: Grade 9 life-science and ecology term

Word study: Root and suffix focus: -logy means the study of a subject.

biotecnologiaBiotechnology enables microbes to produce human insulin.
262genetic engineeringnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: genetic + engineering. Study the complete expression as one field-specific unit.

engenharia genéticaGenetic engineering added a disease-resistance gene to the plant.
263cloningnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Base-form focus: cloning is the dictionary headword; compare its inflected or derived forms in context.

clonagemResearchers use cloning to create many copies of a useful gene.
264stem cellnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: stem + cell. Study the complete expression as one field-specific unit.

célula-troncoA stem cell can produce several kinds of blood cell.
265gene therapynoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: gene + therapy. Study the complete expression as one field-specific unit.

terapia genéticaGene therapy supplied working copies of a missing gene.
266selective breedingnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: selective + breeding. Study the complete expression as one field-specific unit.

criação seletivaFarmers used selective breeding to develop wheat with shorter stems.
267selective pressurenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: selective + pressure. Study the complete expression as one field-specific unit.

pressão seletivaAntibiotic use creates selective pressure favoring resistant bacteria.
268common ancestornoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: common + ancestor. Study the complete expression as one field-specific unit.

ancestral comumHumans and chimpanzees share a common ancestor.
269homologous structurenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: homologous + structure. Study the complete expression as one field-specific unit.

estrutura homólogaA whale flipper and a human arm are a homologous structure in evolutionary comparison.
270analogous structurenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: analogous + structure. Study the complete expression as one field-specific unit.

estrutura análogaA bird wing and an insect wing are an analogous structure.
271vestigial structurenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: vestigial + structure. Study the complete expression as one field-specific unit.

estrutura vestigialA whale's small pelvic bone is a vestigial structure.
272fossil recordnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: fossil + record. Study the complete expression as one field-specific unit.

registro fóssilThe fossil record documents major changes in horse ancestors.
273geographic isolationnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: geographic + isolation. Study the complete expression as one field-specific unit.

isolamento geográficoA new river caused geographic isolation between two lizard populations.
274reproductive isolationnoun
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Field: Grade 9 life-science and ecology term

Word study: Term structure: reproductive + isolation. Study the complete expression as one field-specific unit.

isolamento reprodutivoDifferent mating seasons can create reproductive isolation.
275genetic driftnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: genetic + drift. Study the complete expression as one field-specific unit.

deriva genéticaA storm that kills organisms by chance can cause genetic drift.
276gene flownoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: gene + flow. Study the complete expression as one field-specific unit.

fluxo gênicoWindblown pollen creates gene flow between distant plant populations.
277bottleneck effectnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: bottleneck + effect. Study the complete expression as one field-specific unit.

efeito gargaloA severe wildfire produced a bottleneck effect in the isolated rabbit population.
278founder effectnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: founder + effect. Study the complete expression as one field-specific unit.

1. efeito fundador 2. efeito do fundadorThe island colony shows a founder effect because it began with three birds.
279extinction ratenoun
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Field: Grade 9 life-science and ecology term

Word study: Term structure: extinction + rate. Study the complete expression as one field-specific unit.

taxa de extinçãoHabitat destruction can raise the extinction rate.
280mass extinctionnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: mass + extinction. Study the complete expression as one field-specific unit.

extinção em massaThe end-Permian mass extinction eliminated most marine species.

Vocabulary reading and practice

Page 8 vocabulary review

Review five selected words from page 8.

Vocabulary quiz

Choose the dictionary equivalent for each of 5 selected words.

Sources and curriculum references

These references guide selection and calibration. Definitions, sample sentences, readings, questions, and teaching notes are independently written and reviewed.