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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Words 246–280 of 800
#	Word	Details	Meaning	Sample sentence
246	zygote	noun 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.	the first cell formed when two gametes join	The zygote begins dividing soon after fertilization.
247	fertilization	noun Study Field: Grade 9 life-science and ecology term Word study: Suffix focus: -ization forms a noun for a process of making or becoming.	the joining of gametes to form a zygote	Fertilization combines genetic material from two parents.
248	hereditary pattern	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: hereditary + pattern. Study the complete expression as one field-specific unit.	a regular way in which a trait or condition passes between generations	The pedigree revealed a hereditary pattern linked to a recessive allele.
249	Punnett square	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: Punnett + square. Study the complete expression as one field-specific unit.	a grid used to predict possible allele combinations in offspring	The Punnett square shows a one-in-four chance of the recessive genotype.
250	Mendelian inheritance	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: Mendelian + inheritance. Study the complete expression as one field-specific unit.	inheritance patterns explained by the separation and combination of alleles	A single-gene dominant trait may follow Mendelian inheritance.
251	incomplete dominance	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: incomplete + dominance. Study the complete expression as one field-specific unit.	inheritance in which a heterozygote shows an intermediate phenotype	Red and white flowers produce pink offspring through incomplete dominance.
252	codominance	noun Study Field: Grade 9 life-science and ecology term Word study: Suffix focus: -ance commonly forms a noun naming an action, quality, or state.	inheritance in which both alleles are fully expressed in a heterozygote	Human AB blood type demonstrates codominance.
253	polygenic trait	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: polygenic + trait. Study the complete expression as one field-specific unit.	a characteristic influenced by several genes	Human height is a polygenic trait also affected by environment.
254	sex chromosome	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: sex + chromosome. Study the complete expression as one field-specific unit.	a chromosome involved in determining biological sex and carrying sex-linked genes	The X chromosome is a human sex chromosome.
255	autosome	noun 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.	a chromosome that is not a sex chromosome	Humans normally have twenty-two pairs of each autosome type.
256	genetic variation	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: genetic + variation. Study the complete expression as one field-specific unit.	differences in DNA or inherited traits among individuals	Genetic variation gives natural selection material on which to act.
257	genetic disorder	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: genetic + disorder. Study the complete expression as one field-specific unit.	a health condition caused partly or wholly by changes in genes or chromosomes	A genetic disorder may result from one altered gene or an extra chromosome.
258	genetic carrier	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: genetic + carrier. Study the complete expression as one field-specific unit.	an individual who has a recessive allele without showing the associated trait	A genetic carrier can pass the recessive allele to a child.
259	gene expression	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: gene + expression. Study the complete expression as one field-specific unit.	the process by which information in a gene produces a functional product	Environmental signals can change gene expression without altering the DNA sequence.
260	gene regulation	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: gene + regulation. Study the complete expression as one field-specific unit.	control over when, where, and how strongly a gene is expressed	Gene regulation allows liver cells and nerve cells to use different sets of genes.
261	biotechnology	noun Study Field: Grade 9 life-science and ecology term Word study: Root and suffix focus: -logy means the study of a subject.	the use of living systems or biological processes to develop products and solutions	Biotechnology enables microbes to produce human insulin.
262	genetic engineering	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: genetic + engineering. Study the complete expression as one field-specific unit.	the deliberate modification of an organism's DNA using laboratory methods	Genetic engineering added a disease-resistance gene to the plant.
263	cloning	noun 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.	the production of genetically identical DNA, cells, or organisms	Researchers use cloning to create many copies of a useful gene.
264	stem cell	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: stem + cell. Study the complete expression as one field-specific unit.	an unspecialized cell capable of dividing and developing into other cell types	A stem cell can produce several kinds of blood cell.
265	gene therapy	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: gene + therapy. Study the complete expression as one field-specific unit.	treatment that adds, removes, or alters genetic material in a patient's cells	Gene therapy supplied working copies of a missing gene.
266	selective breeding	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: selective + breeding. Study the complete expression as one field-specific unit.	human-directed reproduction of organisms chosen for desired traits	Farmers used selective breeding to develop wheat with shorter stems.
267	selective pressure	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: selective + pressure. Study the complete expression as one field-specific unit.	an environmental factor that changes which traits improve survival or reproduction	Antibiotic use creates selective pressure favoring resistant bacteria.
268	common ancestor	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: common + ancestor. Study the complete expression as one field-specific unit.	an ancestral population or species shared by two or more later groups	Humans and chimpanzees share a common ancestor.
269	homologous structure	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: homologous + structure. Study the complete expression as one field-specific unit.	a body part similar in underlying anatomy because of shared ancestry	A whale flipper and a human arm are a homologous structure in evolutionary comparison.
270	analogous structure	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: analogous + structure. Study the complete expression as one field-specific unit.	a body part with a similar function but a different evolutionary origin	A bird wing and an insect wing are an analogous structure.
271	vestigial structure	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: vestigial + structure. Study the complete expression as one field-specific unit.	an inherited feature reduced from a more functional form in ancestors	A whale's small pelvic bone is a vestigial structure.
272	fossil record	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: fossil + record. Study the complete expression as one field-specific unit.	the collection and chronological placement of fossils found in Earth's rocks	The fossil record documents major changes in horse ancestors.
273	geographic isolation	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: geographic + isolation. Study the complete expression as one field-specific unit.	physical separation that prevents populations from interbreeding	A new river caused geographic isolation between two lizard populations.
274	reproductive isolation	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: reproductive + isolation. Study the complete expression as one field-specific unit.	a biological barrier that prevents populations from producing fertile offspring together	Different mating seasons can create reproductive isolation.
275	genetic drift	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: genetic + drift. Study the complete expression as one field-specific unit.	random change in allele frequencies, especially in small populations	A storm that kills organisms by chance can cause genetic drift.
276	gene flow	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: gene + flow. Study the complete expression as one field-specific unit.	the movement of alleles between populations through migration and reproduction	Windblown pollen creates gene flow between distant plant populations.
277	bottleneck effect	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: bottleneck + effect. Study the complete expression as one field-specific unit.	loss of genetic variation after a population is sharply reduced	A severe wildfire produced a bottleneck effect in the isolated rabbit population.
278	founder effect	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: founder + effect. Study the complete expression as one field-specific unit.	reduced genetic variation when a new population begins with few individuals	The island colony shows a founder effect because it began with three birds.
279	extinction rate	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: extinction + rate. Study the complete expression as one field-specific unit.	the frequency at which species disappear during a stated period	Habitat destruction can raise the extinction rate.
280	mass extinction	noun Study Field: Grade 9 life-science and ecology term Word study: Term structure: mass + extinction. Study the complete expression as one field-specific unit.	a geologically brief interval in which a large share of species disappears	The 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

Complete 5 review questions for this page.

1. The island colony shows a ___ because it began with three birds.

Answer: founder effect

2. Human height is a ___ also affected by environment.

Answer: polygenic trait

3. Farmers used ___ to develop wheat with shorter stems.

Answer: selective breeding

4. Habitat destruction can raise the ___.

Answer: extinction rate

5. The X chromosome is a human ___.

Answer: sex chromosome

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9th Grade Vocabulary Words

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