Answer:
The owl pellet must be ejected before the owl can eat again.
Explanation: When the pellet moves from the gizzard back up to the proventriculus to be regurgitated it blocks the owl's digestive system which stops them from eating new prey until the pellet is ejected from their body.
I believe it would be the chromosomes of X and Y. XX is Female and XY is Male.
Gel electrophoresis is a technique used to separate DNA fragments according to their size. This is from Khan academy so I believe it is reliable.