sometimes
Most likely the other will start to rot too.
There was only one mouldy apple at the bottom of the barrel!
When one apple in a barrel of apples is bruised, it gives off a ton of ethanol gas that will ruin the rest of the barrel. There's probably way more science behind it, but that's basically it!
This occurs because the rotting apple gives off ethylene, which speeds the ripening of the other apples.
coral the barrell
One on the counter
I'm not sure if this is it but wouldn't it be something like a whole barrel of bad apples ruins one good apple. Again I'm not sure. It is a metaphor one bad person can make a whole group bad so an opposite might be One good person can make a whole group better
A peach is the odd one out because it contains only one seed; all the others have many.
Strawberry. Strawberries grow on the ground (in patches), the others grow on trees.
It is not a law but a time-honored old saying or 'adage': "One bad apple will spoil a barrel." Meaning: If you put one bad thing in with a bunch of good things, eventually the bad thing will ruin all the good ones.
Mixamatosis is one- it cannot be cured and will have to be vaccinated against it. Basically it rots and destroys the rabbits mind.
Greener is one. There are dozens of others.