Question

a rotten apple makes other apple also rotten

Answer 1

Answer:

rotten apple spoils the (whole) barrel

proverb It only takes one bad person, thing, element, etc., to ruin the entire group, situation, project, etc. Refers to the fact that a rotting apple can cause other apples in close proximity to begin to rot as well.

Answer 2

Answer:

$\huge\textsf\green{Verified✓}$

True, similarly a bad person makes its fellow mates bad too.