Hello Neha

I myself have CUCET in 2018 and cleared it. The syllabus of CUCET is what is provided on the website. Sadly, the syllabus includes the entire points not just 7th and 8th. 

They expect the students to have a holistic knowledge of science thatst why every aspect is covered. But don't worry, there will be other people like you who don't know much about theoricial subjects like developmemtal biology. Soo in the end, the level is same.

If you will go through the guidelines you will find the data.

All the best!