An offspring cannot have a trait if neither of its parents has it. Agree or disagree?

Disagree, the offspring can have traits of the from the parent's parent's, if that makes sense

If the P generation are both heterozygous then you have a 25% chance that the offspring will get the recessive trait. If both parents have brown eyes, the child can have blue eyes but it would have to be as a recessive trait from heterozygous parents