Scientists Say

A weekly word defined, in a sentence and in context.

  1. Chemistry

    Scientists Say: Fatty acid

    Fats are important, especially fatty acids. These molecules serve many purposes, but they are all constructed the same way.

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  2. Space

    Scientists Say: Comet

    Comets are small solar system objects. When they pass close to their sun, their melting gases and water give them a tail.

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  3. Life

    Scientists Say: Autophagy

    Cells can break down and recycle their parts for later use. This process — called autophagy — won a scientist a Nobel Prize in 2016.

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  4. Plants

    Scientists Say: Bromeliad

    Bromeliads are plants with long spiky leaves. They are common houseplants, and we even see one in the grocery store — the pineapple.

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  5. Plants

    Scientists Say: Chlorophyll

    Plants can make energy out of sunlight, all thanks to a pigment called chlorophyll.

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  6. Science & Society

    Scientists Say: Stereotype

    This is a belief or explanation for something. But when beliefs get overly simplified, they may no longer be true.

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  7. Earth

    Scientists Say: Permafrost

    In polar regions, it gets cold enough that the very dirt will freeze, and stay frozen. This soil has a special name.

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  8. Ecosystems

    Scientists Say: Tundra

    A tundra is an ecosystem found in Earth’s far north. It has a layer of soil deep underground that remains frozen — sometimes for thousands of years. But the top layer thaws in the summer, allowing plants to grow.

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  9. Environment

    Scientists Say: Aufeis

    Water keeps flowing underground even in the coldest Arctic winters. But when it comes to the surface, it chills out and forms large layers of ice — called aufeis.

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  10. Climate

    Scientists Say: Albedo

    To measure how much light reflects off an object, scientists measure its albedo.

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  11. Earth

    Scientists Say: Hoodoo

    When softer rocks are covered with a harder rock layer, weathering can wear away the softer stone. This will leave behind tall thin towers — hoodoos.

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  12. Genetics

    Scientists Say: DNA sequencing

    All of us have our own individual DNA. Now, scientists can determine what each individual strand is made of — a process called DNA sequencing.

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