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TOEFL Vocabulary: Living systems and ecology

40 medium-tier words, each with a short plain-English definition, followed by a quick quiz to check what stuck.

Test Ninjas Research · Updated October 1, 2026

Habitats, predators, nutrients, migration and photosynthesis: core biology vocabulary that recurs in academic talks and passages about the natural world. Context usually explains the details; knowing the base words keeps you reading at speed.

Most useful for: Complete the Words · Read an Academic Passage · Listen to an Academic Talk.

Living systems and ecology is one of the medium themes in our TOEFL vocabulary list, where you can also find how the tiers work.

The 40 words

Living systems and ecology — Medium tier
#WordMeaningTier
1abundancea large amount of somethingMedium
2agriculturethe growing of crops and raising of animalsMedium
3anatomythe structure of a living bodyMedium
4biodiversitythe variety of living things in an areaMedium
5breedto produce young through reproductionMedium
6cellthe smallest living unit of an organismMedium
7climatelong-term patterns of weather in an areaMedium
8competeto seek a limited resource against othersMedium
9conserveto use carefully so something remainsMedium
10consumeto use up a material or resourceMedium
11decomposeto break down into simpler substancesMedium
12dietthe foods an organism usually eatsMedium
13ecosystemliving things and their physical surroundingsMedium
14endangeredat serious risk of disappearing as a speciesMedium
15environmentconditions surrounding an organism or activityMedium
16evolveto change across generationsMedium
17extinctno longer existing as a living speciesMedium
18fertileable to support growth or reproductionMedium
19habitatthe natural home of a speciesMedium
20herbivorean animal that eats plantsMedium
21inheritto receive traits from earlier generationsMedium
22invasivenonnative and causing harm in a new environmentMedium
23marinerelated to the seaMedium
24migrateto move seasonally or to a new regionMedium
25nutrienta substance needed for growth and healthMedium
26organisman individual living thingMedium
27predatoran animal that hunts other animalsMedium
28preyan animal hunted by another animalMedium
29reproduceto produce offspringMedium
30resiliencethe ability to recover from disturbanceMedium
31speciesa group of related organisms classified as one kindMedium
32symbiosisa close relationship between different speciesMedium
33territoryan area occupied or defended by an organismMedium
34vegetationthe plants growing in an areaMedium
35wildlifeanimals living outside human careMedium
36pollinateto transfer pollen so plants can reproduceMedium
37seedlinga very young plantMedium
38soilthe upper layer of earth where plants growMedium
39microbea living thing too small to see unaidedMedium
40photosynthesisthe process by which plants use light to make foodMedium

Self-check: match the meaning

Cover the table above. Here are 8 of the 40 living systems and ecology words, starting with abundance: choose the word each definition describes.

  1. a large amount of something
    1. abundance
    2. endangered
    3. prey
    4. wildlife
    Show answer

    A. abundance

  2. the smallest living unit of an organism
    1. habitat
    2. cell
    3. territory
    4. photosynthesis
    Show answer

    B. cell

  3. to break down into simpler substances
    1. migrate
    2. soil
    3. decompose
    4. breed
    Show answer

    C. decompose

  4. to change across generations
    1. reproduce
    2. anatomy
    3. consume
    4. evolve
    Show answer

    D. evolve

  5. to receive traits from earlier generations
    1. inherit
    2. vegetation
    3. compete
    4. environment
    Show answer

    A. inherit

  6. an individual living thing
    1. microbe
    2. organism
    3. ecosystem
    4. herbivore
    Show answer

    B. organism

  7. a group of related organisms classified as one kind
    1. biodiversity
    2. fertile
    3. species
    4. nutrient
    Show answer

    C. species

  8. to transfer pollen so plants can reproduce
    1. conserve
    2. marine
    3. resilience
    4. pollinate
    Show answer

    D. pollinate

Using living systems and ecology words on the test

  • In Read an Academic Passage, biodiversity and decompose often carry a paragraph's main point, so check how each one connects to the sentence before it.
  • In Listen to an Academic Talk, a speaker may define fertile or nutrient on the spot; note the definition, not just the word.
  • In Complete the Words you see only the first letters of a word, so practice spelling symbiosis and microbe as well as knowing what they mean.

Other medium themes

Frequently Asked Questions

40, from abundance to photosynthesis, all in the medium tier of our TOEFL list. The self-check quiz on this page tests 8 of them, beginning with abundance.

Language like this is most useful in Read an Academic Passage, Listen to an Academic Talk and Complete the Words. These are general academic words worth recognizing quickly and using when they fit.

Start with cell (the smallest living unit of an organism); evolve (to change across generations); organism (an individual living thing). In Read an Academic Passage, biodiversity and decompose often carry a paragraph's main point, so check how each one connects to the sentence before it.

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