Hello M Ilyas!
Few month ago I take the upgrade from
Java 6 to Java 8 and bought the mocks for enthuware and certainly can said that you need to study several topics found in the Java 7 certification and the mock have include that kind of question.
I studied with the book Oracle Certified Professional Java Se 8 Programmer II Study Guide and this have a complete chapter that talk about the additional objectives for take the upgrade.
So Yes, you need to study this additional topics for can answer question about java 7 technologies (even though some of them are obsolete in java 8)
Greetings