When a tRNA molecule is placed on the ribosome, what happens to the tRNA molecule that was there before it?​

Astudent is looking through a microscope at some cells of an onion root tip. many of these cells are undergoing division since the root tip grows quickly and requires more cells. which cell most recently underwent metaphase? w x y z

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Which are reasons cells undergo cell division?