# Scientists Say

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

1. Life

### Scientists Say: Endocytosis

Small molecules can go into a cell through receptors or even just dissolve into it. But something big? That requires endocytosis.

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2. Physics

### Scientists Say: Absolute zero

Even when we think it’s cold out, most molecules are moving. Only at absolute zero will all of their motions stop.

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3. Animals

### Scientists Say: Copepod

Copepods are tiny crustaceans. They eat phytoplankton and float in the water column, although some live in freshwater and on the sea floor.

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4. Life

### Scientists Say: Strain

These are organisms that belong to the same species, but have definable differences.

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5. Ecosystems

### Scientists Say: Vector

Vectors are used to transfer things. Sometimes the transferred item is a disease, but scientists can also use vectors to insert helpful genes.

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6. Physics

### Scientists Say: Frequency

The distance between one wave peak and another is wavelength. But how fast those peaks are moving along is frequency.

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7. Physics

### Scientists Say: Yottawatt

On Earth, scientists measure energy use in watts. When you have lot of those watts — one million billion billion — you have a yottawatt.

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8. Physics

### Scientists Say: Wavelength

When something travels as a wave — such as light — scientists can measure it by its wavelength, the distances between the peaks.

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9. Physics

### Scientists Say: Watt

Say Watt? This is a unit used to measure the flow of energy being used.

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10. Math

### Scientists Say: Y-axis

The bars on a graph tell you nothing unless you know what they mean. The lines on the sides can let you know.

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11. Life

### Scientists Say: Yeast

For some people, yeast bring to mind slimy infections. But these little fungal beasts are used to make bread rise, too.

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12. Math

### Scientists Say: X-axis

The bars on a graph tell you nothing unless you know what they mean. The lines on the sides can let you know.

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