An independent variable is

An independent variable is exactly what it sounds like. It is a variable that stands alone and isn't changed by the other variables you are trying to measure. For example, someone's age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren't going to change a person's age. In fact, when you are looking for some kind of relationship between variables you are trying to see if the independent variable causes some kind of change in the other variables, or dependent variables.

the dna of humans and mice is almost 92% similar. this similarity indicates that . mice have a tail, while humans have a tailbone. the tailbone is a structure in humans.yes it's true.

yes, because even though a theory has a  lot of evidence to support it, it is not always true