| Word | Definition & Example |
|---|---|
| adaptation n. |
A change in an organism that improves its survival in a particular environment. "The cactus's thick stem is an adaptation to arid conditions." Collocations: evolutionary adaptation, behavioural adaptation |
| habitat n. |
The natural environment in which a species lives. "Coral reefs serve as a habitat for thousands of fish species." Collocations: natural habitat, habitat loss |
| ecosystem n. |
A community of organisms together with their physical environment. "The Amazon ecosystem supports tens of millions of species." Collocations: marine ecosystem, fragile ecosystem |
| species n. |
A group of organisms that can reproduce together. "Over 8 million species are estimated to exist on Earth." Collocations: endangered species, invasive species |
| organism n. |
Any living thing — plant, animal, fungus, bacterium. "Single-celled organisms dominated Earth for billions of years." Collocations: microscopic organism, complex organism |
| evolution n. |
Gradual change in inherited characteristics over generations. "Darwin's theory of evolution unified previously unconnected biological observations." Collocations: biological evolution, evolution by natural selection |
| natural selection n. |
The mechanism by which traits favourable to survival become more common over time. "Natural selection explains why polar bears developed thick white fur." Collocations: pressure of natural selection |
| mutation n. |
A change in the genetic material of a cell. "Random mutations are the raw material of evolutionary change." Collocations: genetic mutation, beneficial mutation |
| predator n. |
An animal that hunts and eats other animals. "Wolves are apex predators in many North American ecosystems." Collocations: apex predator, predator-prey relationship |
| prey n. |
An animal that is hunted by another animal for food. "Rabbits are the primary prey of foxes in temperate regions." Collocations: prey species, fall prey to |
| photosynthesis n. |
The process by which plants convert sunlight into chemical energy. "Photosynthesis releases oxygen as a by-product." Collocations: the process of photosynthesis |
| respiration n. |
The process by which cells convert nutrients into energy. "Cellular respiration occurs in the mitochondria." Collocations: cellular respiration, aerobic respiration |
| genome n. |
The complete set of genes in an organism. "Sequencing the human genome took over a decade and billions of dollars." Collocations: human genome, genome sequencing |
| chromosome n. |
A thread-like structure that carries genetic information. "Humans have 46 chromosomes arranged in 23 pairs." Collocations: chromosome pair, sex chromosome |
| enzyme n. |
A protein that speeds up chemical reactions in living organisms. "Digestive enzymes break down food into absorbable molecules." Collocations: digestive enzyme, enzyme activity |
| metabolism n. |
The chemical processes that maintain life in an organism. "A high metabolism means the body burns calories quickly." Collocations: fast metabolism, metabolic rate |
| microbe n. |
A microscopic organism, especially a bacterium. "Microbes in the soil convert dead plants into nutrients." Collocations: harmful microbe, beneficial microbe |
| nutrient n. |
A substance that provides nourishment for growth. "Nitrogen and phosphorus are essential plant nutrients." Collocations: essential nutrient, nutrient cycle |
| biodiversity n. |
The variety of life forms in a given ecosystem or on Earth. "Tropical rainforests have the highest biodiversity on the planet." Collocations: loss of biodiversity, biodiversity hotspot |
| pollination n. |
The transfer of pollen from one flower to another, enabling fertilisation. "Bees provide essential pollination for one third of food crops." Collocations: cross-pollination, pollination by insects |
| dormant adj. |
Inactive but capable of becoming active later. "Bears remain dormant throughout the winter months." Collocations: dormant volcano, dormant cell |
| thrive v. |
To grow and develop strongly. "Some bacteria thrive in extreme environments like deep-sea vents." Collocations: thrive in conditions |
| dominant adj. |
Most influential or successful in a particular environment. "Conifers are the dominant tree species in boreal forests." Collocations: dominant species, dominant gene |
| disrupt v. |
To interrupt or interfere with the normal course of something. "Climate change has disrupted migration patterns of many bird species." Collocations: disrupt the ecosystem, disrupt the cycle |
| specimen n. |
An individual animal or plant used as an example or for study. "The botanist collected specimens of every fern species in the valley." Collocations: rare specimen, biological specimen |
How this vocabulary appears on the TOEFL
Biology & Life Sciences terms appear directly in passages and audio across Reading · Listening. The questions you'll see most frequently target this vocabulary are paraphrase identification (the test rewords a sentence using a synonym from this list), inference questions (you need the term's meaning to follow the argument), and reference questions (the term is the antecedent of a pronoun in another sentence). Knowing the term plus one or two natural collocations lets you decode passages faster and recognise paraphrases on the answer choices without re-reading.
How to study this list effectively
Don't try to memorise the whole list in one sitting. Effective vocabulary study works in three passes: (1) recognise — read each entry once until the word feels familiar; (2) retrieve — cover the definitions and try to recall each one from the word alone; (3) produce — write a sentence of your own that uses the word in a TOEFL context. Spaced repetition over 5–7 days will make the words stick far better than a single intensive review session. Pair this list with a practice test in the same section so you encounter the words in real test contexts.
Practise this vocabulary on real TOEFL tests
- Reading practice tests — passages on academic topics
- Listening practice tests — campus conversations and academic talks
- Full-length practice tests — vocabulary in context across all four sections
- More TOEFL vocabulary by topic