This week on The Missing Workbook
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Word
English Vocabulary
Pick a CEFR level (A1–C2, plus C2+ for rare words beyond the CEFR scale) — A1 is the friendliest place to start — and browse its words grouped by topic: travel, food, the body, emotions, and more. Each word shows its meaning, example sentences, and US/UK pronunciation.
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All 27,899 wordsC2+ is beyond the official CEFR scale: rare, specialist, and literary words kept for reference.
48 words
system
A2
/ˈsɪstəm/
A set of connected parts that work together as a whole.
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DNA
B2
/ˌdiˌɛnˈeɪ/
The substance in living cells that carries genetic information and passes on characteristics.
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species
B2
/ˈspiːʃiːz/
A group of living things that are similar and can breed with one another.
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sperm
C1
/spɜɹm/
a male reproductive cell that can fertilize an egg cell
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evolution
B2
/ˌɛvəˈluʃ(ə)n/
The gradual process by which something changes and develops over time.
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selection
B1
/səˈlɛkʃən/
a range of things to choose from
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biology
B1
/baɪˈɑ.lə.d͡ʒi/
The science that studies living things such as plants and animals.
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inherit
B2
/ɪnˈhɛɹɪt/
To receive money, property, or a title from someone after they die.
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clone
A2
/kloʊn/
A copy of something made to look or work just like the original.
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fossil
C1
/ˈfɑsl̩/
the preserved remains or shape of a plant or animal that lived long ago
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extinction
B1
/ɪkˈstɪŋkʃən/
The situation in which a species or group no longer exists.
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parasite
C1
/ˈpæɹəˌsaɪt/
An animal or plant that lives on or inside another and feeds off it.
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habitat
B1
/ˈhæb.ɪ.tæt/
The natural place where a plant or animal lives.
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organism
B1
/ɔʳˈɡan.ɪzəm/
A single living thing, such as an animal, plant, or microbe.
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genetics
B1
/dʒəˈnɛtɪks/
The branch of biology that studies how characteristics are passed from parents to children.
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mammal
C2
/ˈmæməl/
any warm-blooded vertebrate having the skin more or less covered with hair
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biologist
B1
/baɪˈɑː.lə.dʒɪst/
a scientist who studies living organisms and the processes of life
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reproduction
C1
/ˌɹiːpɹəˈdʌkʃən/
The biological process by which living things produce offspring.
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embryo
C1
/ˈɛmbɹi.oʊ/
a plant, animal, or human in the earliest stages of development
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metabolism
C1
/məˈtæb.əˌlɪz.əm/
the set of chemical processes by which a living organism converts substances into energy and materials needed for life, growth, and repair
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ecosystem
B1
/ˈikoʊˌsɪstəm/
All the living things in an area and the way they affect each other and their environment.
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genome
C1
/ˈd͡ʒiː.noʊm/
The complete set of genetic information in an organism.
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membrane
B2
/ˈmɛm.bɹeɪn/
a thin pliable sheet of material
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respiration
B2
/ɹɛspɪˈɹeɪʃən/
The process of breathing in and out.
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classification
B2
/ˌklæsɪfɪˈkeɪʃən/
The act of arranging things into groups based on shared qualities.
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botany
B2
/ˈbɑ.tə.ni/
The scientific study of plants.
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chromosome
C1
/ˈkɹoʊməˌsoʊm/
a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order
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ecology
B1
/ɪˈkɑ.lə.d͡ʒi/
The study of the relationships between living things and their environment.
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microbe
B2
/ˈmaɪkɹoʊb/
A tiny living thing too small to see without a microscope, such as a bacterium that can cause disease.
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fertilization
C2
/ˌfɝːtəlɪˈzeɪʃən/
the union of male and female gametes to begin the development of a new organism
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zoology
C2
/zoʊˈɑləd͡ʒi/
The branch of biology that studies animals.
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symbiosis
C2
/sɪmbaɪˈoʊsɪs/
The occurrence of two different or opposing things in the same time and place.
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heredity
C1
/həˈɹɛdəti/
Hereditary transmission of the physical and genetic qualities of parents to their offspring; the biological law by which living beings tend to repeat their characteristics in their descendants.
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biotechnology
B2
/ˌbaɪoʊˌtɛkˈnɑːlədʒi/
The use of living things, such as cells or bacteria, to make medicines, foods, and other useful products.
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paleontology
C2
/ˌpeɪliənˈtɑːlədʒi/
the scientific study of prehistoric life through fossils and other remains preserved in rocks
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mitosis
C2
/maɪˈtoʊ.sɪs/
cell-nuclear division in which duplicated chromosomes separate into two genetically equivalent nuclei
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invertebrate
C1
/ɪnˈvɝː.tə.brət/
an animal without a backbone, such as an insect, mollusk, or worm
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meiosis
C2
/maɪˈoʊ.sɪs/
cell division in which one diploid cell undergoes two divisions to produce four haploid cells
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genus
C2+
/ˈdʒinəs/
a taxonomic rank grouping related species above the species level
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anatomy
C2+
/əˈnætəmi/
the bodily structure of an organism, or its study
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mutation
C2+
/mjuˈteɪʃən/
a change in form or structure, especially a heritable change in genetic material
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ovum
C2+
/ˈoʊvəm/
a mature female reproductive cell; an egg cell
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amphibian
C2+
/æmˈfɪbiən/
a cold-blooded vertebrate, like a frog, that lives both in water and on land
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physiology
C2+
/ˌfɪziˈɑlədʒi/
the branch of biology dealing with the functions of living organisms and their parts
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reptile
C2+
/ˈrɛptaɪl/
a cold-blooded scaly vertebrate such as a snake, lizard, or crocodile
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photosynthesis
B2
/ˌfoʊ.toʊˈsɪn.θə.sɪs/
the process by which plants, algae, and some bacteria use light energy to make energy-rich chemical compounds
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genotype
C1
/ˈd͡ʒɛnəˌtaɪp/
the genetic constitution of an organism, especially the combination of gene variants it has for a particular characteristic
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kill off
A2
to cause many members of a living group to die
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