Yes. You look like your father = You resemble your father in many ways. You and your father have many similarities although you still both have differences. You look just like your father. = You look exactly like your father. Both 'look like' and 'look just like' are quite similar except the difference is the second one is used for more emphasis.

Craig's answer is right. I wanted to add that "look like" can be used in another way, for example: It looks like it's going to rain tomorrow. The pattern is: "It looks like X is/are going to..." and it means that based on evidence, or things you've seen or heard, you are certain that something is going to happen. In this pattern, you can't say "looks just like," only "looks like."