The phrase that best describes a meteoroid is "Small pieces of rock and dust in space"
Meteoroids are small bodies of the solar system. They are rocks between 100 μm -50 m in diameter that are smaller than comets and asteroids and bigger than cosmic dust. They commonly are fragments of comets and asteroids that had been separated from them by heavy impacts. When a meteoroid enters the atmosphere, it burns, and the glow that this burn produces is what we call "shooting stars". However, the correct definition is the mentioned above.
Biologists used the world's largest single-celled organism, an aquatic alga called Caulerpa taxifolia, to study the nature of structure and form in plants. It is a single cell that can grow to a length of six to twelve inches.