Unit 1 is where Chapter 4 of the NCERT Solutions for Class 11 Biology is categorized. It is advised that students gather the question papers from the previous years and study them for a better grade in order to know the questions that can be anticipated from this chapter. According to current trends, approximately 10% of the questions on the board exam may be from this unit. In this chapter, the differences between the structures and forms of various animals are briefly explained.