Is there a way to make an if condition to ignore certain lines in a script?

I have a script which offers a variety of options to the user. Depending on the option, the script may ask more or less things, and do different things. So, to make it logical, I will have to do if conditions in the whole code. For example, if the first block of code is suppose to work when user chooses option, say, number 1 or 3, I'll have to surround the block with an if condition, and then putting an elif or else condition for the rest of options. Is there a way to make an if condition to ignore certain lines of code?