If I get a zero on a 25 pt. quiz, how much will it affect my grade of B?!?

[Jkdivas123]

My biology teacher put the vocab online with limited time and i needed one more question! and since i couldn't complete it on the amount time i got a zero! Please help me i'm really freaking out right now because i can't have a F! I have a B of 83% about, so please tell me how much it will affect my grade. Please serious answers.