Which bird is flightless

ostrich is flightless...

Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratite's (ostriches, emu, cassowaries, rheas, and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g).

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the denominator has a very specific role.

name and explain one of the event that occurs during meiosis that increases the variation in offspring even more than simple reproduction?