Given a scientific passage and an answer, generate a question for the given answer.

Q: Passage: Nobody really has such colorful eyes! The colors were added digitally after the photo was taken. They represent all the different colors of light. Light is a form of energy that travels in waves. Light of different colors has different wavelengths. Answer: wavelengths

A: Different colors of light differ in terms of which important attribute?
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Q: Passage: Equinox comes halfway between the two solstices. At equinoxes, the Sun's rays shine most directly at the Equator ( Figure below ). The daylight and nighttime hours are exactly equal on an equinox. The autumnal, or fall, equinox happens on September 22 or 23. The vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Answer: equinox

A: What event occurs between the two solstices?
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Q: Passage: The cell is the smallest unit of structure and function of all living organisms. A cell is also the smallest unit of life, with single-celled organisms present on this planet for over 3.5 billion years. Single-celled ( unicellular ) organisms like bacteria are obviously composed of just one cell, whereas multicellular organisms can be composed of trillions of cells. Multicellular organisms include protists (though single-celled protists also exist), fungi, plants and animals. Most plant and animal cells are between 1 and 100 m and therefore can only be observed under the microscope. Answer: the cell

A:
What is the smallest unit of structure and function of all living organisms?
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