Answer:

1. A fallacy can be defined as a flaw or error in reasoning. It is an error in reasoning resulting in a false conclusion or misconception. A fallacious argument can be deductively invalid (a formal fallacy) or one that has false premises or insufficient inductive strength (an informal fallacy). At its most basic, a logical fallacy refers to a defect in the reasoning of an argument that causes the conclusion(s) to be invalid, unsound, or weak. It is important to study fallacies so you can avoid them in the arguments you make.

2. Anything that is verifiable and repeatable is likely to be true. If not verifiable and repeatable, then it may well be completely false, or at least partially false. At times even the false statement will also act as truth and truth needs some evidence to prove it is truth. When it is claimed that the truth of a premise is based on the fact that it has not been proven true then it is likely to be fallacy. Credible sources should be used to state that your claim is true and not because this is what you believe is true that would lead to be only your mere opinion.